def METHOD_NAME(self, item, identity_field=None):
    identity = {}
    from_ = item
    if isinstance(item, dict) and 'data' in item:
        from_ = item['data']['message'][identity_field]
    identity['username'] = from_.get('username', None)
    identity['email'] = None
    identity['name'] = from_.get('first_name', None)
    return identity