code: def from_float(cls, other):
      # The whole flow is float -> observed -> quantized
      # This class does observed -> quantized only
      raise NotImplementedError(
          "It looks like you are trying to convert a "
          "non-observed MHA module. Please, see "
          "the examples on quantizable MHAs."
      )
  
imports: import torch
  from warnings import warn
label_desc: Use image node_id 2 for calling the MultiheadAttention obj's underlying member method code with example usage: obj.from_float(cls, other) without return types