def ImportAllParams(task_root=_TASK_ROOT, task_dirs=_TASK_DIRS):
  # Import all ModelParams to ensure that they are added to the global registry.
  for task in task_dirs:
    # By our code repository convention, there is a params.py under the task's
    # params directory. params.py imports _all_ modules that may registers a
    # model param.
    _Import('{}.{}.params.params'.format(task_root, task))