code: def test_replaygain_preamp(self):
      signal = load_signal(loud_rg_flac_file)
      base_spl = signal.spl()
      rg_sig = load_signal(loud_rg_flac_file, replaygain_mode="track")
      # Remember, ffmpeg will limit gain to avoid clipping,
      # so the SPL difference is non-obvious here.
      self.assertTrue(base_spl > rg_sig.spl())
      # Preamp on a file with track RG at -12.44 should happily go to -6.44dB
      pre_rg_sig = load_signal(
          loud_rg_flac_file,
          replaygain_mode="track",
          replaygain_preamp=+6.0,
      )
      self.assertAlmostEqual(
          rg_sig.spl() + 6.0, pre_rg_sig.spl(), places=3
      )
  
imports: from __future__ import absolute_import, division, print_function
  import io
  import unittest
  from os.path import join
  from madmom.io.audio import *
  from .None import AUDIO_PATH, DATA_PATH
label_desc: Use image node_id 13 for calling the TestLoadAudioFileFunction obj's underlying member method code with example usage: obj.test_replaygain_preamp() without return types