code: def from_observed(cls, other):
      # The whole flow is float -> observed -> quantized
      # This class does float -> observed only
      # See nn.quantized.MultiheadAttention
      raise NotImplementedError(
          "It looks like you are trying to prepare an "
          "MHA module. Please, see "
          "the examples on quantizable MHAs."
      )
  
file_path: pytorch/torch/ao/nn/quantizable/modules/activation.py
imports: import torch
  import torch.jit
  from torch import nn
  import torch.nn.functional
  from torch import Tensor
  from typing import Optional, Tuple
  import warnings
label_desc: Use image node_id 5 for calling the MultiheadAttention obj's underlying member method code with example usage: obj.from_observed(cls, other) without return types