code: def transform_ast(self, node, ctx):
      return FlipSignTransformer(ctx).visit(node)
  
imports: import threading
  import unittest
  import gast
  from nvidia.dali._autograph.pyct import transformer
  from nvidia.dali._autograph.pyct import transpiler
label_desc: Use image node_id 3 for calling the TestTranspiler obj's underlying member method code with example usage: obj.transform_ast(node, ctx) and returns: FlipSignTransformer