code: def loop(
      model, cond_blob, external_blobs, loop_model, cond_model=None
  ):
      """Loop"""
      add_while_op(
          model.net,
          cond_blob,
          external_blobs,
          loop_model.net,
          cond_model.net if cond_model else None,
      )
  
label_desc: Use image node_id 2 for calling a global function with example usage: loop(model, cond_blob, external_blobs, loop_model, cond_model) without return types