code: def _populate_audio_file(self):
          
          self.log(u"Populate audio file...")
          if self.audio_file_path_absolute is not None:
              self.log([u"audio_file_path_absolute is '%s'", self.audio_file_path_absolute])
              self.audio_file = AudioFile(
                  file_path=self.audio_file_path_absolute,
                  logger=self.logger
              )
              self.audio_file.read_properties()
          else:
              self.log(u"audio_file_path_absolute is None")
          self.log(u"Populate audio file... done")
docs: Create the ``self.audio_file`` object by reading
          the audio file at ``self.audio_file_path_absolute``.