class_docstr: CrossPooler for DRL.
class_docstr_tok: ["CrossPooler","for","DRL","."]
code: def forward(self, hidden_states, hidden_mask):
      # We "pool" the model by simply taking the hidden state corresponding
      # to the first token.
      _ = hidden_mask
      hidden_states = self.ln_pool(hidden_states)
      pooled_output = hidden_states[:, 0]
      pooled_output = self.dense(pooled_output)
      pooled_output = self.activation(pooled_output)
      return pooled_output
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import logging
  import torch
  from torch import nn
  from towhee.models.drl.until_module import LayerNorm
  from collections import OrderedDict
label_desc: Use image node_id 2 for calling the CrossPooler obj's underlying member method code with example usage: obj.forward(hidden_states, hidden_mask) and returns: pooled_output