def km3h5concat(input_files, output_file, n_events=None, **kwargs):
    """Concatenate KM3HDF5 files via pipeline."""
    from km3pipe import Pipeline    # noqa
    from km3pipe.io import HDF5Pump, HDF5Sink    # noqa

    pipe = Pipeline()
    pipe.attach(HDF5Pump, filenames=input_files, **kwargs)
    pipe.attach(StatusBar, every=250)
    pipe.attach(HDF5Sink, filename=output_file, **kwargs)
    pipe.drain(n_events)
Concatenate KM3HDF5 files via pipeline.