code: def add_dict_to_hash(a_hash, a_dict):
      
      if a_dict is None:
          return
      for k, v in a_dict.items():
          a_hash.update(b'\x00' + k.encode('utf-8') + b'\x00' + v.encode('utf-8'))
docs: Adds `a_dict` to `a_hash`
  
      Args:
         a_hash (`Hash`): the secure hash, e.g created by hashlib.md5
         a_dict (dict[string, [string]]): the dictionary to add to the hash