code: def _test_fn(x, y, z):
      return x + 2 * y + 4 * z
  
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow.python.framework import test_util
  from tf_quant_finance.models.legacy import brownian_motion_utils
label_desc: Use image node_id 1 for calling a global function with example usage: _test_fn(x, y, z) and returns: unknown