code: def _evaluate(self, Gs, Gs_kwargs, num_gpus):
      raise NotImplementedError
  
imports: import os
  import time
  import hashlib
  import numpy
  import tensorflow
  import dnnlib
  import dnnlib.tflib
  from training import misc
  from training import dataset
label_desc: Use image node_id 8 for calling the MetricBase obj's underlying member method code with example usage: obj._evaluate(Gs, Gs_kwargs, num_gpus) without return types