def METHOD_NAME(self, item, identity_field=None):
    identity = {}
    identity['username'] = None
    identity['email'] = None
    identity['name'] = None
    if identity_field is None:
        identity_field = self.get_field_author()
    tweet = item  # by default a specific user dict is expected
    if isinstance(item, dict) and 'data' in item:
        tweet = item['data']
    if identity_field in tweet:
        identity['username'] = tweet[identity_field]['screen_name']
        identity['name'] = tweet[identity_field]['name']
    return identity