How to use the lkml.lexer.Lexer function in lkml

Args:
        stream: File object or string containing LookML to be parsed

    Raises:
        TypeError: If stream is neither a string or a file object

    """

    if isinstance(stream, io.TextIOWrapper):
        text = stream.read()
    elif isinstance(stream, str):
        text = stream
    else:
        raise TypeError("Input stream must be a string or file object.")
    lexer = Lexer(text)
    tokens = lexer.scan()
    parser = Parser(tokens)
    result = parser.parse()
    return result