code: def BERTPretrainingHead(n_classes):
      return (tl.Branch(BERTClassifierHead(n_classes), BERTMLMHead()),)
  
imports: import os
  import pathlib
  import urllib
  import zipfile
  import gin
  import jax
  import tensorflow
  from trax import fastmath
  from trax import layers
  from trax.fastmath import numpy
label_desc: Use image node_id 5 for calling a global function with example usage: BERTPretrainingHead(n_classes) and returns: tl