code: def get_cql_models(app, connection=None, keyspace=None):
      
      from .models import DjangoCassandraModel
      models = []
      single_cassandra_connection = len(list(get_cassandra_connections())) == 1
      is_default_connection = connection == DEFAULT_DB_ALIAS or \
          single_cassandra_connection
  
      for name, obj in inspect.getmembers(app):
          cql_model_types = (
              cqlengine.models.Model,
              DjangoCassandraModel
          )
          if (
              inspect.isclass(obj) and issubclass(obj, cql_model_types) and
              not obj.__abstract__
          ):
              if obj.__connection__ == connection or \
                      (obj.__connection__ is None and is_default_connection) or \
                      obj.__connection__ is None and obj.__keyspace__ is not None and obj.__keyspace__ == keyspace:
                  models.append(obj)
  
      return models
docs: :param app: django models module
      :param connection: connection name
      :param keyspace: keyspace
      :return: list of all cassandra.cqlengine.Model within app that should be
      synced to keyspace.