code: def set_client_format(self, desc):
          
          assert desc.mFormatID == AUDIO_ID_PCM
          check(_coreaudio.ExtAudioFileSetProperty(
              self._obj, PROP_CLIENT_DATA_FORMAT, ctypes.sizeof(desc),
              ctypes.byref(desc)
          ))
          self._client_fmt = desc
docs: Get the client format description. This describes the
          encoding of the data that the program will read from this
          object.