parameters: (name, default, help, flag_values=FLAGS, **args)
docstring: Registers a flag whose value can be any string.
docstring_summary: Registers a flag whose value can be any string.
docstring_tokens: Registers a flag whose value can be any string .
function: def DEFINE_string(name, default, help, flag_values=FLAGS, **args):
    """Registers a flag whose value can be any string."""
    parser = ArgumentParser()
    serializer = ArgumentSerializer()
    DEFINE(parser, name, default, help, flag_values, serializer, **args)
function_tokens: def DEFINE_string ( name , default , help , flag_values = FLAGS , * * args ) : parser = ArgumentParser ( ) serializer = ArgumentSerializer ( ) DEFINE ( parser , name , default , help , flag_values , serializer , * * args )