def guess_compression(block):
if block.startswith(b'<STR_LIT>'):<EOL><INDENT>return '<STR_LIT>'<EOL><DEDENT>elif block.startswith(b'<STR_LIT>'):<EOL><INDENT>return '<STR_LIT>'<EOL><DEDENT>return None<EOL>
Return the compression type of the data.

    Args:
        block (bytes): block of data to identify

    Returns:
        One of None, 'bz2', or 'xz'