code: public Binder filterForward(int index, MethodHandle... functions) {
          Binder filtered = this;
  
          for (int i = 0; i < functions.length; i++) {
              filtered = filtered.filter(index + i, functions[i]);
          }
  
          return filtered;
      }
docs: Filter incoming arguments, from the given index, replacing each with the
  result of calling the associated function in the given list. This version
  guarantees left-to-right evaluation of filter functions, potentially at
  the cost of a more complex handle tree.
  
  @param index     the index of the first argument to filter
  @param functions the array of functions to transform the arguments
  @return a new Binder