code: def __call__(self, x, past):
      assert x.shape[-1] == self.nx
  
      a, present = self.attn(self.norm1(x), past=past)
      x = x + a
      m = self.mlp(self.norm2(x))
      x = x + m
  
      return x, present
  
imports: import json
  import os
  import sys
  import jax.numpy
  import numpy
  import objax
  from objax.variable import TrainVar
label_desc: Use image node_id 2 for calling the Block obj's underlying member method code with example usage: obj.__call__(x, past) and returns: x,  present