code: def is_dsub_operation(op):
    
    if not is_pipeline(op):
      return False
  
    for name in ['dsub-version', 'job-id', 'job-name', 'user-id']:
      if not get_label(op, name):
        return False
  
    return True
docs: Determine if a pipelines operation is a dsub request.
  
    We don't have a rigorous way to identify an operation as being submitted
    by dsub. Our best option is to check for certain fields that have always
    been part of dsub operations.
  
    - labels: job-id, job-name, and user-id have always existed. The dsub-version
              label has always existed for the google-v2 provider.
  
    Args:
      op: a pipelines operation.
  
    Returns:
      Boolean, true if the pipeline run was generated by dsub.