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 matchsubinclude(f):
            for prefix, matcherargs in subincludes:
                if f.startswith(prefix):
                    mf = submatchers.get(prefix)
                    if mf is None:
                        mf = match(*matcherargs)
                        submatchers[prefix] = mf

                    if mf(f[len(prefix) :]):
                        return True
            return False