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 open_pager(self):
        "Open the selected item with the system's pager"
        data = self.get_selected_item()
        if data['type'] == 'Submission':
            text = '\n\n'.join((data['permalink'], data['text']))
            self.term.open_pager(text)
        elif data['type'] == 'Comment':
            text = '\n\n'.join((data['permalink'], data['body']))
            self.term.open_pager(text)
        else:
            self.term.flash()