code: public <T1> Mutable<T1> mapInputToObj(final Function<T1, Byte> fn) {
          final MutableByte host = this;
          return new Mutable<T1>() {
              @Override
              public Mutable<T1> set(final T1 value) {
                  host.set(fn.apply(value));
                  return this;
              }
  
          };
      }
docs: Use the supplied function to perform a lazy transform operation when getValue is called
  <pre>
  {@code
  MutableByte mutable = MutablByte.fromExternal(()->!this.value,val->!this.value);
  Mutable<Byte> withOverride = mutable.mapInputToObj(b->{
  if(override)
  return 1b;
  return b;
  });
  
  }
  </pre>
  
  
  @param fn Map function to be applied to the input when set is called
  @return Mutable that lazily applies the provided function when set is called to the input value