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 display_name(self):
        """
        Find the most appropriate display name for a user: look for a "display_name", then
        a "real_name", and finally fall back to the always-present "name".
        """
        for k in self._NAME_KEYS:
            if self._raw.get(k):
                return self._raw[k]
            if "profile" in self._raw and self._raw["profile"].get(k):
                return self._raw["profile"][k]
        return self._raw["name"]