class_docstr: Unit tests for variable tracing using.
code: def test_lambda_with_closure_vars(self):
      w = objax.TrainVar(jn.zeros(5))
      b = objax.TrainVar(jn.zeros(1))
  
      loss = (
          lambda x, y: 0.5
          * ((y - jn.dot(x, w.value) + b.value) ** 2).mean()
      )
  
      vc = objax.util.find_used_variables(loss)
      self.assertDictEqual(vc, {"w": w, "b": b})
  
file_path: objax/tests/tracing.py
imports: import unittest
  import numpy
  import jax.numpy
  import objax
  from objax.zoo.dnnet import DNNet
label_desc: Use image node_id 5 for calling the TestTracing obj's underlying member method code with example usage: obj.test_lambda_with_closure_vars() without return types