code: def mul_zero_simplify(expr):
      if expr[0] != "#Mul":
          return None
      for i in expr[1:]:
          if i[0] == 0:
              return (0,)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow
label_desc: Use image node_id 20 for calling a global function with example usage: mul_zero_simplify(expr) and returns: None, int