code: def call(self, x, y, z=None):
      # `z` has to be put first due to the order of operations issue with
      # torch backend.
      return 3 * z + x + 2 * y
  
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 1 for calling the OpWithMultipleInputs obj's underlying member method code with example usage: obj.call(x, y, z) and returns: unknown