def METHOD_NAME(self, data):
    chunk = next(self._data_chunks(data))[0]
    chunk_type = type(chunk).__name__
    inputs = [signal
              for signal in self.widget.get_signals("inputs")
              if isinstance(chunk, signal.type)]
    if not inputs:
        raise ValueError(f"no signal handlers for '{chunk_type}'")
    if len(inputs) > 1:
        inputs = [signal for signal in inputs if signal.default]
        if len(inputs) != 1:
            raise ValueError(
                f"multiple signal handlers for '{chunk_type}'")
    return inputs[0].handler