docstr: Check name conflict raises a ValueError.
docstr_tok: ["Check","name","conflict","raises","a","ValueError","."]
code: def test_name_conflict(self):
      """Check name conflict raises a ValueError."""
      vc1 = objax.VarCollection([("a", objax.TrainVar(jn.zeros(1)))])
      vc2 = objax.VarCollection([("a", objax.TrainVar(jn.ones(1)))])
      with self.assertRaises(ValueError):
          vc1 + vc2
  
      with self.assertRaises(ValueError):
          vc1.update(vc2)
  
      with self.assertRaises(ValueError):
          vc1["a"] = objax.TrainVar(jn.ones(1))
  
file_path: objax/tests/var_collection.py
imports: import re
  import unittest
  import jax.numpy
  import objax
  from objax.zoo import wide_resnet
label_desc: Use image node_id 4 for calling the TestVarCollection obj's underlying member method code with example usage: obj.test_name_conflict() without return types