diff --git a/afl/src/bolts/serdeany.rs b/afl/src/bolts/serdeany.rs
index c79ced0ce7..53e58fcfda 100644
--- a/afl/src/bolts/serdeany.rs
+++ b/afl/src/bolts/serdeany.rs
@@ -18,7 +18,7 @@ pub fn unpack_type_id(id: TypeId) -> u64 {
     unsafe { *(&id as *const _ as *const u64) }
 }
 
-/// An any object
+/// A (de)serializable Any trait
 pub trait SerdeAny: Any + erased_serde::Serialize {
     /// returns this as Any trait
     fn as_any(&self) -> &dyn Any;
@@ -142,8 +142,12 @@ macro_rules! create_serde_registry_for_trait {
                 finalized: false,
             };
 
+            /// This shugar must be used to register all the structs which
+            /// have trait objects that can be serialized and deserialized in the program
             pub struct RegistryBuilder {}
+
             impl RegistryBuilder {
+                /// Register a given struct type for trait object (de)serialization
                 pub fn register<T>()
                 where
                     T: $trait_name + Serialize + serde::de::DeserializeOwned,
@@ -153,6 +157,7 @@ macro_rules! create_serde_registry_for_trait {
                     }
                 }
 
+                /// Finalize the registry, no more registrations are allowed after this call
                 pub fn finalize() {
                     unsafe {
                         REGISTRY.finalize();
@@ -161,6 +166,8 @@ macro_rules! create_serde_registry_for_trait {
             }
 
             #[derive(Serialize, Deserialize)]
+            /// A (de)serializable anymap containing (de)serializable trait objects registered
+            /// in the registry
             pub struct SerdeAnyMap {
                 map: HashMap<u64, Box<dyn $trait_name>>,
             }
diff --git a/afl/src/mutators/mutations.rs b/afl/src/mutators/mutations.rs
index b43963370d..c960e97dea 100644
--- a/afl/src/mutators/mutations.rs
+++ b/afl/src/mutators/mutations.rs
@@ -488,7 +488,7 @@ where
     R: Rand,
 {
     let size = input.bytes().len();
-    let off = rand.below((size +1) as u64) as usize;
+    let off = rand.below((size + 1) as u64) as usize;
     let mut len = 1 + rand.below(16) as usize;
 
     if size + len > mutator.max_size() {
@@ -517,7 +517,7 @@ where
     R: Rand,
 {
     let size = input.bytes().len();
-    let off = rand.below((size +1) as u64) as usize;
+    let off = rand.below((size + 1) as u64) as usize;
     let mut len = 1 + rand.below(16) as usize;
 
     if size + len > mutator.max_size() {
@@ -549,7 +549,7 @@ where
     R: Rand,
 {
     let size = input.bytes().len();
-    let off = rand.below((size +1) as u64) as usize;
+    let off = rand.below((size + 1) as u64) as usize;
     let mut len = 1 + rand.below(16) as usize;
 
     if size + len > mutator.max_size() {
@@ -700,7 +700,7 @@ where
     let from = rand.below(other_size as u64) as usize;
     let to = rand.below(size as u64) as usize;
     let mut len = rand.below((other_size - from) as u64) as usize;
-    
+
     if size + len > mutator.max_size() {
         if mutator.max_size() > size {
             len = mutator.max_size() - size;
diff --git a/afl/src/mutators/scheduled.rs b/afl/src/mutators/scheduled.rs
index 22a510f286..fb0901626b 100644
--- a/afl/src/mutators/scheduled.rs
+++ b/afl/src/mutators/scheduled.rs
@@ -304,8 +304,7 @@ where
         scheduled.add_mutation(mutation_bytesswap);
 
         scheduled.add_mutation(mutation_tokeninsert);
-        /*scheduled.add_mutation(mutation_tokenreplace);
-        */
+        scheduled.add_mutation(mutation_tokenreplace);
 
         scheduled.add_mutation(mutation_crossover_insert);
         scheduled.add_mutation(mutation_crossover_replace);
diff --git a/afl/src/mutators/token_mutations.rs b/afl/src/mutators/token_mutations.rs
index 93bd0fe9db..2ce7a52ab8 100644
--- a/afl/src/mutators/token_mutations.rs
+++ b/afl/src/mutators/token_mutations.rs
@@ -15,6 +15,7 @@ use serde::{Deserialize, Serialize};
 
 use mutations::buffer_copy;
 
+/// A state metadata holding a list of tokens
 #[derive(Serialize, Deserialize)]
 pub struct TokensMetadata {
     tokens: Vec<Vec<u8>>,
@@ -32,9 +33,7 @@ impl SerdeAny for TokensMetadata {
 
 impl TokensMetadata {
     pub fn new(tokens: Vec<Vec<u8>>) -> Self {
-        Self {
-            tokens: tokens
-        }
+        Self { tokens: tokens }
     }
 }
 
@@ -64,9 +63,9 @@ where
         return Ok(MutationResult::Skipped);
     }
     let token = &meta.tokens[rand.below(meta.tokens.len() as u64) as usize];
-    
+
     let size = input.bytes().len();
-    let off = rand.below((size +1) as u64) as usize;
+    let off = rand.below((size + 1) as u64) as usize;
     let mut len = token.len();
 
     if size + len > mutator.max_size() {
@@ -80,7 +79,7 @@ where
     input.bytes_mut().resize(size + len, 0);
     buffer_self_copy(input.bytes_mut(), off, off + len, size - off);
     buffer_copy(input.bytes_mut(), token, 0, off, len);
-    
+
     Ok(MutationResult::Mutated)
 }
 
@@ -88,7 +87,7 @@ where
 pub fn mutation_tokenreplace<I, M, R, S>(
     _: &mut M,
     rand: &mut R,
-    state: &S,
+    state: &mut S,
     input: &mut I,
 ) -> Result<MutationResult, AflError>
 where
@@ -114,9 +113,9 @@ where
         return Ok(MutationResult::Skipped);
     }
     let token = &meta.tokens[rand.below(meta.tokens.len() as u64) as usize];
-    
+
     let off = rand.below(size as u64) as usize;
-    
+
     let mut len = token.len();
     if off + len > size {
         len = size - off;
diff --git a/afl/src/observers/map.rs b/afl/src/observers/map.rs
new file mode 100644
index 0000000000..0b4254845e
--- /dev/null
+++ b/afl/src/observers/map.rs
@@ -0,0 +1,340 @@
+use alloc::string::{String, ToString};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    bolts::{
+        ownedref::{ArrayMut, Cptr},
+        tuples::Named,
+    },
+    observers::Observer,
+    AflError,
+};
+
+/// A MapObserver observes the static map, as oftentimes used for afl-like coverage information
+pub trait MapObserver<T>: Observer
+where
+    T: Default + Copy,
+{
+    /// Get the map
+    fn map(&self) -> &[T];
+
+    /// Get the map (mutable)
+    fn map_mut(&mut self) -> &mut [T];
+
+    /// Get the number of usable entries in the map (all by default)
+    fn usable_count(&self) -> usize {
+        self.map().len()
+    }
+
+    /// Get the initial value for reset()
+    fn initial(&self) -> T;
+
+    /// Get the initial value for reset()
+    fn initial_mut(&mut self) -> &mut T;
+
+    /// Set the initial value for reset()
+    fn set_initial(&mut self, initial: T);
+
+    /// Reset the map
+    #[inline]
+    fn reset_map(&mut self) -> Result<(), AflError> {
+        // Normal memset, see https://rust.godbolt.org/z/Trs5hv
+        let initial = self.initial();
+        let cnt = self.usable_count();
+        for i in self.map_mut()[0..cnt].iter_mut() {
+            *i = initial;
+        }
+        Ok(())
+    }
+}
+
+/// The Map Observer retrieves the state of a map,
+/// that will get updated by the target.
+/// A well-known example is the AFL-Style coverage map.
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(bound = "T: serde::de::DeserializeOwned")]
+pub struct StdMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    map: ArrayMut<T>,
+    initial: T,
+    name: String,
+}
+
+impl<T> Observer for StdMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn pre_exec(&mut self) -> Result<(), AflError> {
+        self.reset_map()
+    }
+}
+
+impl<T> Named for StdMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn name(&self) -> &str {
+        self.name.as_str()
+    }
+}
+
+impl<T> MapObserver<T> for StdMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn map(&self) -> &[T] {
+        self.map.as_slice()
+    }
+
+    #[inline]
+    fn map_mut(&mut self) -> &mut [T] {
+        self.map.as_mut_slice()
+    }
+
+    #[inline]
+    fn initial(&self) -> T {
+        self.initial
+    }
+
+    #[inline]
+    fn initial_mut(&mut self) -> &mut T {
+        &mut self.initial
+    }
+
+    #[inline]
+    fn set_initial(&mut self, initial: T) {
+        self.initial = initial
+    }
+}
+
+impl<T> StdMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    /// Creates a new MapObserver
+    pub fn new(name: &'static str, map: &'static mut [T]) -> Self {
+        let initial = if map.len() > 0 { map[0] } else { T::default() };
+        Self {
+            map: ArrayMut::Cptr((map.as_mut_ptr(), map.len())),
+            name: name.to_string(),
+            initial,
+        }
+    }
+
+    /// Creates a new MapObserver from a raw pointer
+    pub fn new_from_ptr(name: &'static str, map_ptr: *mut T, len: usize) -> Self {
+        unsafe {
+            let initial = if len > 0 { *map_ptr } else { T::default() };
+            StdMapObserver {
+                map: ArrayMut::Cptr((map_ptr, len)),
+                name: name.to_string(),
+                initial,
+            }
+        }
+    }
+}
+
+/// Overlooking a variable bitmap
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(bound = "T: serde::de::DeserializeOwned")]
+pub struct VariableMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    map: ArrayMut<T>,
+    size: Cptr<usize>,
+    initial: T,
+    name: String,
+}
+
+impl<T> Observer for VariableMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn pre_exec(&mut self) -> Result<(), AflError> {
+        self.reset_map()
+    }
+}
+
+impl<T> Named for VariableMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn name(&self) -> &str {
+        self.name.as_str()
+    }
+}
+
+impl<T> MapObserver<T> for VariableMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    #[inline]
+    fn map(&self) -> &[T] {
+        self.map.as_slice()
+    }
+
+    #[inline]
+    fn map_mut(&mut self) -> &mut [T] {
+        self.map.as_mut_slice()
+    }
+
+    #[inline]
+    fn usable_count(&self) -> usize {
+        *self.size.as_ref()
+    }
+
+    #[inline]
+    fn initial(&self) -> T {
+        self.initial
+    }
+
+    #[inline]
+    fn initial_mut(&mut self) -> &mut T {
+        &mut self.initial
+    }
+
+    #[inline]
+    fn set_initial(&mut self, initial: T) {
+        self.initial = initial
+    }
+}
+
+impl<T> VariableMapObserver<T>
+where
+    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
+{
+    /// Creates a new MapObserver
+    pub fn new(name: &'static str, map: &'static mut [T], size: &usize) -> Self {
+        let initial = if map.len() > 0 { map[0] } else { T::default() };
+        Self {
+            map: ArrayMut::Cptr((map.as_mut_ptr(), map.len())),
+            size: Cptr::Cptr(size as *const _),
+            name: name.into(),
+            initial,
+        }
+    }
+
+    /// Creates a new MapObserver from a raw pointer
+    pub fn new_from_ptr(
+        name: &'static str,
+        map_ptr: *mut T,
+        max_len: usize,
+        size_ptr: *const usize,
+    ) -> Self {
+        unsafe {
+            let initial = if max_len > 0 { *map_ptr } else { T::default() };
+            VariableMapObserver {
+                map: ArrayMut::Cptr((map_ptr, max_len)),
+                size: Cptr::Cptr(size_ptr),
+                name: name.into(),
+                initial,
+            }
+        }
+    }
+}
+
+/// Map observer with hitcounts postprocessing
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(bound = "M: serde::de::DeserializeOwned")]
+pub struct HitcountsMapObserver<M>
+where
+    M: MapObserver<u8>,
+{
+    base: M,
+}
+
+static COUNT_CLASS_LOOKUP: [u8; 256] = [
+    0, 1, 2, 0, 8, 8, 8, 8, 16, 16, 16, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
+    32, 32, 32, 32, 32, 32, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
+    64, 64, 64, 64, 64, 64, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+];
+
+impl<M> Observer for HitcountsMapObserver<M>
+where
+    M: MapObserver<u8>,
+{
+    #[inline]
+    fn pre_exec(&mut self) -> Result<(), AflError> {
+        self.reset_map()
+    }
+
+    #[inline]
+    fn post_exec(&mut self) -> Result<(), AflError> {
+        for x in self.map_mut().iter_mut() {
+            *x = COUNT_CLASS_LOOKUP[*x as usize];
+        }
+        Ok(())
+    }
+}
+
+impl<M> Named for HitcountsMapObserver<M>
+where
+    M: MapObserver<u8>,
+{
+    #[inline]
+    fn name(&self) -> &str {
+        self.base.name()
+    }
+}
+
+impl<M> MapObserver<u8> for HitcountsMapObserver<M>
+where
+    M: MapObserver<u8>,
+{
+    #[inline]
+    fn map(&self) -> &[u8] {
+        self.base.map()
+    }
+
+    #[inline]
+    fn map_mut(&mut self) -> &mut [u8] {
+        self.base.map_mut()
+    }
+
+    #[inline]
+    fn usable_count(&self) -> usize {
+        self.base.usable_count()
+    }
+
+    #[inline]
+    fn initial(&self) -> u8 {
+        self.base.initial()
+    }
+
+    #[inline]
+    fn initial_mut(&mut self) -> &mut u8 {
+        self.base.initial_mut()
+    }
+
+    #[inline]
+    fn set_initial(&mut self, initial: u8) {
+        self.base.set_initial(initial);
+    }
+}
+
+impl<M> HitcountsMapObserver<M>
+where
+    M: MapObserver<u8>,
+{
+    /// Creates a new MapObserver
+    pub fn new(base: M) -> Self {
+        Self { base: base }
+    }
+}
diff --git a/afl/src/observers/mod.rs b/afl/src/observers/mod.rs
index 355acc31c0..152ac9bfd3 100644
--- a/afl/src/observers/mod.rs
+++ b/afl/src/observers/mod.rs
@@ -1,17 +1,12 @@
-extern crate num;
+pub mod map;
+pub use map::*;
 
-use alloc::{
-    string::{String, ToString},
-    vec::Vec,
-};
+use alloc::string::{String, ToString};
 use core::time::Duration;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    bolts::{
-        ownedref::{ArrayMut, Cptr},
-        tuples::{MatchNameAndType, MatchType, Named, TupleList},
-    },
+    bolts::tuples::{MatchNameAndType, MatchType, Named, TupleList},
     utils::current_time,
     AflError,
 };
@@ -152,335 +147,6 @@ impl Named for TimeObserver {
     }
 }
 
-/// A MapObserver observes the static map, as oftentimes used for afl-like coverage information
-pub trait MapObserver<T>: Observer
-where
-    T: Default + Copy,
-{
-    /// Get the map
-    fn map(&self) -> &[T];
-
-    /// Get the map (mutable)
-    fn map_mut(&mut self) -> &mut [T];
-
-    /// Get the number of usable entries in the map (all by default)
-    fn usable_count(&self) -> usize {
-        self.map().len()
-    }
-
-    /// Get the initial value for reset()
-    fn initial(&self) -> T;
-
-    /// Get the initial value for reset()
-    fn initial_mut(&mut self) -> &mut T;
-
-    /// Set the initial value for reset()
-    fn set_initial(&mut self, initial: T);
-
-    /// Reset the map
-    #[inline]
-    fn reset_map(&mut self) -> Result<(), AflError> {
-        // Normal memset, see https://rust.godbolt.org/z/Trs5hv
-        let initial = self.initial();
-        let cnt = self.usable_count();
-        for i in self.map_mut()[0..cnt].iter_mut() {
-            *i = initial;
-        }
-        Ok(())
-    }
-}
-
-/// The Map Observer retrieves the state of a map,
-/// that will get updated by the target.
-/// A well-known example is the AFL-Style coverage map.
-#[derive(Serialize, Deserialize, Clone, Debug)]
-#[serde(bound = "T: serde::de::DeserializeOwned")]
-pub struct StdMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    map: ArrayMut<T>,
-    initial: T,
-    name: String,
-}
-
-impl<T> Observer for StdMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn pre_exec(&mut self) -> Result<(), AflError> {
-        self.reset_map()
-    }
-}
-
-impl<T> Named for StdMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn name(&self) -> &str {
-        self.name.as_str()
-    }
-}
-
-impl<T> MapObserver<T> for StdMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn map(&self) -> &[T] {
-        self.map.as_slice()
-    }
-
-    #[inline]
-    fn map_mut(&mut self) -> &mut [T] {
-        self.map.as_mut_slice()
-    }
-
-    #[inline]
-    fn initial(&self) -> T {
-        self.initial
-    }
-
-    #[inline]
-    fn initial_mut(&mut self) -> &mut T {
-        &mut self.initial
-    }
-
-    #[inline]
-    fn set_initial(&mut self, initial: T) {
-        self.initial = initial
-    }
-}
-
-impl<T> StdMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    /// Creates a new MapObserver
-    pub fn new(name: &'static str, map: &'static mut [T]) -> Self {
-        let initial = if map.len() > 0 { map[0] } else { T::default() };
-        Self {
-            map: ArrayMut::Cptr((map.as_mut_ptr(), map.len())),
-            name: name.to_string(),
-            initial,
-        }
-    }
-
-    /// Creates a new MapObserver from a raw pointer
-    pub fn new_from_ptr(name: &'static str, map_ptr: *mut T, len: usize) -> Self {
-        unsafe {
-            let initial = if len > 0 { *map_ptr } else { T::default() };
-            StdMapObserver {
-                map: ArrayMut::Cptr((map_ptr, len)),
-                name: name.to_string(),
-                initial,
-            }
-        }
-    }
-}
-
-/// Overlooking a variable bitmap
-#[derive(Serialize, Deserialize, Clone, Debug)]
-#[serde(bound = "T: serde::de::DeserializeOwned")]
-pub struct VariableMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    map: ArrayMut<T>,
-    size: Cptr<usize>,
-    initial: T,
-    name: String,
-}
-
-impl<T> Observer for VariableMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn pre_exec(&mut self) -> Result<(), AflError> {
-        self.reset_map()
-    }
-}
-
-impl<T> Named for VariableMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn name(&self) -> &str {
-        self.name.as_str()
-    }
-}
-
-impl<T> MapObserver<T> for VariableMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    #[inline]
-    fn map(&self) -> &[T] {
-        self.map.as_slice()
-    }
-
-    #[inline]
-    fn map_mut(&mut self) -> &mut [T] {
-        self.map.as_mut_slice()
-    }
-
-    #[inline]
-    fn usable_count(&self) -> usize {
-        *self.size.as_ref()
-    }
-
-    #[inline]
-    fn initial(&self) -> T {
-        self.initial
-    }
-
-    #[inline]
-    fn initial_mut(&mut self) -> &mut T {
-        &mut self.initial
-    }
-
-    #[inline]
-    fn set_initial(&mut self, initial: T) {
-        self.initial = initial
-    }
-}
-
-impl<T> VariableMapObserver<T>
-where
-    T: Default + Copy + 'static + serde::Serialize + serde::de::DeserializeOwned,
-{
-    /// Creates a new MapObserver
-    pub fn new(name: &'static str, map: &'static mut [T], size: &usize) -> Self {
-        let initial = if map.len() > 0 { map[0] } else { T::default() };
-        Self {
-            map: ArrayMut::Cptr((map.as_mut_ptr(), map.len())),
-            size: Cptr::Cptr(size as *const _),
-            name: name.into(),
-            initial,
-        }
-    }
-
-    /// Creates a new MapObserver from a raw pointer
-    pub fn new_from_ptr(
-        name: &'static str,
-        map_ptr: *mut T,
-        max_len: usize,
-        size_ptr: *const usize,
-    ) -> Self {
-        unsafe {
-            let initial = if max_len > 0 { *map_ptr } else { T::default() };
-            VariableMapObserver {
-                map: ArrayMut::Cptr((map_ptr, max_len)),
-                size: Cptr::Cptr(size_ptr),
-                name: name.into(),
-                initial,
-            }
-        }
-    }
-}
-
-/// Map observer with hitcounts postprocessing
-#[derive(Serialize, Deserialize, Clone, Debug)]
-#[serde(bound = "M: serde::de::DeserializeOwned")]
-pub struct HitcountsMapObserver<M>
-where
-    M: MapObserver<u8>,
-{
-    base: M,
-}
-
-static COUNT_CLASS_LOOKUP: [u8; 256] = [
-    0, 1, 2, 0, 8, 8, 8, 8, 16, 16, 16, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
-    32, 32, 32, 32, 32, 32, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
-    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
-    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
-    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
-    64, 64, 64, 64, 64, 64, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
-];
-
-impl<M> Observer for HitcountsMapObserver<M>
-where
-    M: MapObserver<u8>,
-{
-    #[inline]
-    fn pre_exec(&mut self) -> Result<(), AflError> {
-        self.reset_map()
-    }
-
-    #[inline]
-    fn post_exec(&mut self) -> Result<(), AflError> {
-        for x in self.map_mut().iter_mut() {
-            *x = COUNT_CLASS_LOOKUP[*x as usize];
-        }
-        Ok(())
-    }
-}
-
-impl<M> Named for HitcountsMapObserver<M>
-where
-    M: MapObserver<u8>,
-{
-    #[inline]
-    fn name(&self) -> &str {
-        self.base.name()
-    }
-}
-
-impl<M> MapObserver<u8> for HitcountsMapObserver<M>
-where
-    M: MapObserver<u8>,
-{
-    #[inline]
-    fn map(&self) -> &[u8] {
-        self.base.map()
-    }
-
-    #[inline]
-    fn map_mut(&mut self) -> &mut [u8] {
-        self.base.map_mut()
-    }
-
-    #[inline]
-    fn usable_count(&self) -> usize {
-        self.base.usable_count()
-    }
-
-    #[inline]
-    fn initial(&self) -> u8 {
-        self.base.initial()
-    }
-
-    #[inline]
-    fn initial_mut(&mut self) -> &mut u8 {
-        self.base.initial_mut()
-    }
-
-    #[inline]
-    fn set_initial(&mut self, initial: u8) {
-        self.base.set_initial(initial);
-    }
-}
-
-impl<M> HitcountsMapObserver<M>
-where
-    M: MapObserver<u8>,
-{
-    /// Creates a new MapObserver
-    pub fn new(base: M) -> Self {
-        Self { base: base }
-    }
-}
-
 #[cfg(feature = "std")]
 #[cfg(test)]
 mod tests {
diff --git a/fuzzers/libfuzzer_libpng/src/mod.rs b/fuzzers/libfuzzer_libpng/src/mod.rs
index aa649261f6..bc1a23442c 100644
--- a/fuzzers/libfuzzer_libpng/src/mod.rs
+++ b/fuzzers/libfuzzer_libpng/src/mod.rs
@@ -4,7 +4,7 @@
 use std::{env, path::PathBuf};
 
 use afl::{
-    bolts::{shmem::AflShmem, tuples::tuple_list, serdeany::RegistryBuilder},
+    bolts::{serdeany::RegistryBuilder, shmem::AflShmem, tuples::tuple_list},
     corpus::{Corpus, InMemoryCorpus},
     events::setup_restarting_mgr,
     events::SimpleStats,
@@ -92,15 +92,13 @@ fn fuzz(corpus_dirs: Vec<PathBuf>, broker_port: u16) -> Result<(), AflError> {
 
     // Create a PNG dictionary of not existing
     if state.metadata().get::<TokensMetadata>().is_none() {
-        state.add_metadata(TokensMetadata::new(
-            vec![
-                vec![137, 80, 78, 71, 13, 10, 26, 10], // PNG header
-                "IHDR".as_bytes().to_vec(),
-                "IDAT".as_bytes().to_vec(),
-                "PLTE".as_bytes().to_vec(),
-                "IEND".as_bytes().to_vec(),
-            ]
-        ));
+        state.add_metadata(TokensMetadata::new(vec![
+            vec![137, 80, 78, 71, 13, 10, 26, 10], // PNG header
+            "IHDR".as_bytes().to_vec(),
+            "IDAT".as_bytes().to_vec(),
+            "PLTE".as_bytes().to_vec(),
+            "IEND".as_bytes().to_vec(),
+        ]));
     }
 
     // Setup a basic mutator with a mutational stage