def __init__(self, path_to_dir, check_all_files=True, backend=None):
        """
        Initialize an OpenPMD time series with various methods to diagnose the
        data

        Parameter
        ---------
        path_to_dir : string
            The path to the directory where the openPMD files are.
            For the moment, only HDF5 files are supported. There should be
            one file per iteration, and the name of the files should end
            with the iteration number, followed by '.h5' (e.g. data0005000.h5)

        check_all_files: bool, optional
            Check that all the files in the timeseries are consistent
            (i.e. that they contain the same fields and particles,
            with the same metadata)
            For fast access to the files, this can be changed to False.

        backend: string
            Backend to be used for data reading. Can be `openpmd-api`
            or `h5py`. If not provided will use `openpmd-api` if available
            and `h5py` otherwise.
        """
        OpenPMDTimeSeries.__init__(self,
                                   path_to_dir,
                                   check_all_files=check_all_files,
                                   backend=backend)
    def __init__( self, path_to_dir, check_all_files=True ):
        """
        Initialize an OpenPMD time series with various methods to diagnose the
        data

        Parameter
        ---------
        path_to_dir : string
            The path to the directory where the openPMD files are.
            For the moment, only HDF5 files are supported. There should be
            one file per iteration, and the name of the files should end
            with the iteration number, followed by '.h5' (e.g. data0005000.h5)

        check_all_files: bool, optional
            Check that all the files in the timeseries are consistent
            (i.e. that they contain the same fields and particles,
            with the same metadata)
            For fast access to the files, this can be changed to False.
        """
        OpenPMDTimeSeries.__init__( self, path_to_dir,
                                    check_all_files=check_all_files )