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 refresh_content(self, order=None, name=None):
        "Re-download comments and reset the page index"

        order = order or self.content.order
        url = name or self.content.name

        with self.term.loader('Refreshing page'):
            self.content = SubmissionContent.from_url(
                self.reddit, url, self.term.loader, order=order,
                max_comment_cols=self.config['max_comment_cols'])
        if not self.term.loader.exception:
            self.nav = Navigator(self.content.get, page_index=-1)