def add_header(input_array, codec, length, param):
return struct.pack(mmtf.utils.constants.NUM_DICT[<NUM_LIT:4>], codec) +struct.pack(mmtf.utils.constants.NUM_DICT[<NUM_LIT:4>], length) +struct.pack(mmtf.utils.constants.NUM_DICT[<NUM_LIT:4>], param) + input_array<EOL>
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