code: def testDupField(self):
      with self.assertRaises(ValueError):
          schema.Struct(("a", schema.Scalar()), ("a", schema.Scalar()))
  
imports: from caffe2.python import core, schema
  import numpy
  import unittest
  import pickle
  import random
label_desc: Use image node_id 13 for calling the TestDB obj's underlying member method code with example usage: obj.testDupField() without return types