def add(self, elem, replace=False):
        """Add a requirement.

        :param elem: a string or :class:`Requirement` instance.
        :param replace: if `True`, packages in the set with the same name will
            be removed first.
        """
        if isinstance(elem, text_type):
            elem = Requirement.coerce(elem)
        if replace and elem in self:
            self.remove(elem)
        super(Requirements, self).add(elem)
def _kindpatsalwaysmatch(kindpats):
    """ "Checks whether the kindspats match everything, as e.g.
    'relpath:.' does.
    """
    for kind, pat, source in kindpats:
        # TODO: update me?
        if pat != "" or kind not in ["relpath", "glob"]:
            return False
    return True