<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def django_table_names(self, only_existing=False, **kwargs):
 """ Returns a list of all table names that have associated cqlengine models and are present in settings.INSTALLED_APPS. """


        all_models = list(chain.from_iterable(self.cql_models.values()))
        tables = [model.column_family_name(include_keyspace=False)
                  for model in all_models]

        return tables