def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def setup_args(parser=None):
    if parser is None:
        parser = ParlaiParser(True, True, 'Check tasks for common errors')
    # Get command line arguments
    parser.add_argument('-ltim', '--log-every-n-secs', type=float, default=2)
    parser.add_argument('-d', '--display-examples', type='bool', default=False)
    parser.set_defaults(datatype='train:stream:ordered')
    return parser