class_docstr: A Mock BertEncoder
class_docstr_tok: ["A","Mock","BertEncoder"]
code: def forward(
      self,
      input_ids,
      attention_mask,
      position_ids,
      img_feat,
      img_pos_feat,
      img_masks,
      gather_index,
  ):
      print(
          f"forward, input_ids={input_ids}, attention_mask={attention_mask}, position_ids={position_ids}"
          f"img_feat={img_feat}, img_pos_feat={img_pos_feat}, img_masks={img_masks}, gather_index={gather_index}"
      )
      return torch.ones(2, 1), torch.ones(2, 1), torch.ones(2, 1)
  
file_path: towhee/tests/unittests/models/lightning_dot/test_lightning_dot.py
imports: import unittest
  import torch
  from torch import nn
  from towhee.models.lightning_dot.bi_encoder import BiEncoder
label_desc: Use image node_id 2 for calling the MockBertEncoder obj's underlying member method code with example usage: obj.forward(input_ids, attention_mask, position_ids, img_feat, img_pos_feat, img_masks, gather_index) and returns: torch,  torch,  torch