code: def add_header(input_array, codec, length, param):
      
      return struct.pack(mmtf.utils.constants.NUM_DICT[4], codec) + \
             struct.pack(mmtf.utils.constants.NUM_DICT[4], length) + \
             struct.pack(mmtf.utils.constants.NUM_DICT[4], param) + input_array
docs: Add the header to the appropriate array.
      :param the encoded array to add the header to
      :param the codec being used
      :param the length of the decoded array
      :param the parameter to add to the header
      :return the prepended encoded byte array