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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def add_config_path(path):
 """Select config parser by file extension and add path into parser. """

    if not os.path.isfile(path):
        warnings.warn("Config file does not exist: {path}".format(path=path))
        return False

    # select parser by file extension
    _base, ext = os.path.splitext(path)
    if ext and ext[1:] in PARSERS:
        parser = ext[1:]
    else:
        parser = PARSER
    parser_class = PARSERS[parser]

    _check_parser(parser_class, parser)
    if parser != PARSER:
        msg = (
            "Config for {added} parser added, but used {used} parser. "
            "Set up right parser via env var: "
            "export LUIGI_CONFIG_PARSER={added}"
        )
        warnings.warn(msg.format(added=parser, used=PARSER))

    # add config path to parser
    parser_class.add_config_path(path)
    return True