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_ccode_constants_mathh():
    assert ccode(exp(1)) == "M_E"
    assert ccode(pi) == "M_PI"
    assert ccode(oo) == "HUGE_VAL"
    assert ccode(-oo) == "-HUGE_VAL"