class_docstr: Patch Merging Layer.
  Args:
      input_resolution (`tuple[int]`):
          Resolution of input feature.
      dim (`int`):
          Number of input channels.
      norm_layer (`nn.Module`):
          Normalization layer.  Default: nn.LayerNorm
code: def flops(self):
      h, w = self.input_resolution
      flops = h * w * self.dim
      flops += (h // 2) * (w // 2) * 4 * self.dim * 2 * self.dim
      return flops
  
imports: import torch
  from torch import nn
label_desc: Use image node_id 4 for calling the PatchMerging obj's underlying member method code with example usage: obj.flops() and returns: flops