'Add the issues in ``issue_keys`` to the ``epic_id``.
:param epic_id: the epic to add issues to
:param issue_keys: the issues to add to the epic
:param ignore_epics: ignore any issues listed in ``issue_keys`` that are epics'

def add_issues_to_epic(self, epic_id, issue_keys, ignore_epics=True):

    if (self._options[u'agile_rest_path'] != GreenHopperResource.GREENHOPPER_REST_PATH):
        raise NotImplementedError(u'JIRA    Agile    Public    API    does    not    support    this    request')
    data = {}
    data[u'issueKeys'] = issue_keys
    data[u'ignoreEpics'] = ignore_epics
    url = self._get_url((u'epics/%s/add' % epic_id), base=self.AGILE_BASE_URL)
    return self._session.put(url, data=json.dumps(data))
