code: def forward(self, x):
      return _fast_layer_norm(
          x, self.weight, self.bias, self.epsilon, self.memory_efficient
      )
  
file_path: apex/apex/contrib/layer_norm/layer_norm.py
imports: import torch
  from torch.nn import init
  from apex._autocast_utils import _cast_if_autocast_enabled
  import fast_layer_norm
label_desc: Use image node_id 3 for calling the FastLayerNorm obj's underlying member method code with example usage: obj.forward(x) and returns: _fast_layer_norm