code: def forward(self, x):
      return x.mean(self.dim, keepdim=not self.flatten)
  
imports: from typing import Optional, Tuple, Union
  import torch
  import torch.nn
  import torch.nn.functional
  from .format import get_spatial_dim, get_channel_dim
label_desc: Use image node_id 2 for calling the FastAdaptiveAvgPool obj's underlying member method code with example usage: obj.forward(x) and returns: x