code: def backward_compatible(self):
      self.sample_softmax = -1
  
imports: import sys
  import math
  import functools
  import numpy
  import torch
  import torch.nn
  import torch.nn.functional
  from proj_adaptive_softmax import ProjectedAdaptiveLogSoftmax, Projection
  from log_uniform_sampler import LogUniformSampler, sample_logits
  from fmoe import FMoETransformerMLP
label_desc: Use image node_id 2 for calling the MemTransformerLM obj's underlying member method code with example usage: obj.backward_compatible() without return types