code: def forward(self, x):
      return self.block(x)
  
imports: import torch
  import torch.nn
  import torch.nn.functional
  from contextlib import ExitStack
  from .resnet import ResNetBackbone
  from .basic_blocks import select_activation_function
  from .basic_blocks import SeparableConv2d
label_desc: Use image node_id 2 for calling the _DeepLabHead obj's underlying member method code with example usage: obj.forward(x) and returns: self