code: def _prod(l):
      r = 1
      for p in l:
          r *= p
      return r
  
imports: import torch
  import torchaudio.prototype.functional
  from parameterized import param, parameterized
  from torchaudio_unittest.common_utils import nested_params, TestBaseMixin
  from .dsp_utils import exp_sigmoid, freq_ir, oscillator_bank, sinc_ir
label_desc: Use image node_id 1 for calling a global function with example usage: _prod(l) and returns: r