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 test_below_or_equal_to():
    """Less than or equal to y."""
    p = are.not_below_or_equal_to(3)
    ps = [p(x) for x in range(1, 6)]
    assert ps == [False, False, False, True, True]