code: def forward(self, x):
      x = self.c_attn(x)
      query, key, value = x.split(self.split_size, dim=2)
      query = self.split_heads(query)
      key = self.split_heads(key, k=True)
      value = self.split_heads(value)
      a = self._attn(query, key, value)
      a = self.merge_heads(a)
      a = self.c_proj(a)
      a = self.resid_dropout(a)
      return a
  
imports: from __future__ import with_statement
  from __future__ import division
  from __future__ import absolute_import
  import copy
  import io
  import json
  import logging
  import math
  import re
  import tarfile
  import numpy
  import torch
  from torch.nn import Parameter
  from allennlp.common.checks import ConfigurationError
  from allennlp.common.file_utils import cached_path
  from allennlp.common.from_params import FromParams
  from io import open
label_desc: Use image node_id 5 for calling the Attention obj's underlying member method code with example usage: obj.forward(x) and returns: a