code: def ensure_task_params_are_complete(task_descriptors):
    
    for task_desc in task_descriptors:
      for param in [
          'labels', 'envs', 'inputs', 'outputs', 'input-recursives',
          'output-recursives'
      ]:
        if not task_desc.task_params.get(param):
          task_desc.task_params[param] = set()
docs: For each task, ensure that each task param entry is not None.