code: def testMul(self):
      self._testBinOp([1, 2], [3, 4], [3, 8], lambda a, b: a.__mul__(b))
  
imports: from collections import abc
  import numpy
  import tensorflow.compat.v2
  from trax.tf_numpy.numpy_impl import arrays
  from trax.tf_numpy.numpy_impl import math_ops
label_desc: Use image node_id 9 for calling the ArrayTest obj's underlying member method code with example usage: obj.testMul() without return types