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 uipath(self, f):
        """Convert repo path to a display path.  If patterns or -I/-X were used
        to create this matcher, the display path will be relative to cwd.
        Otherwise it is relative to the root of the repo."""
        return (self._relativeuipath and self.rel(f)) or self.abs(f)