def is_composite(self):
    return self.parts or all(pval.producer is not self for pval in self.outputs)
Given a set of forums and a user, returns the list of forums that are not visible
dataset/ETHPy150Open GoogleCloudPlatform/DataflowPythonSDK/google/cloud/dataflow/pipeline.py/AppliedPTransform.is_composite--crossover with--dataset/ETHPy150Open ellmetha/django-machina/machina/apps/forum_permission/handler.py/PermissionHandler._get_hidden_forum_ids