def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def test_between_or_equal_to():
    """Greater than or equal to y and less than or equal to z."""
    p = are.between_or_equal_to(3, 3)
    ps = [p(x) for x in range(1, 6)]
    assert ps == [False, False, True, False, False]