class_docstr: Generate random syntactically-valid Python ASTs.
code: def generate_expression(self):
      desired_node = ExpressionSampler().sample()
      # Go get the generator method and run it
      method = "generate_" + desired_node.__name__
      generator = getattr(self, method)
      return generator()
  
imports: import random
  import string
  import gast
  import numpy
  from nvidia.dali._autograph.pyct import gast_util
  from nvidia.dali._autograph.pyct import templates
label_desc: Use image node_id 8 for calling the CodeGenerator obj's underlying member method code with example usage: obj.generate_expression() and returns: generator