code: def test_input_conversion(self):
      x = np.ones((2,))
      y = np.ones((2,))
      z = knp.ones((2,))  # mix
      if backend.backend() == "torch":
          z = z.cpu()
      op = OpWithMultipleInputs()
      out = op(x, y, z)
      self.assertTrue(backend.is_tensor(out))
      self.assertAllClose(out, 6 * np.ones((2,)))
  
imports: import numpy
  from keras import backend
  from keras import testing
  from keras.backend.common import keras_tensor
  from keras.ops import numpy
  from keras.ops import operation
label_desc: Use image node_id 5 for calling the OperationTest obj's underlying member method code with example usage: obj.test_input_conversion() without return types