def write1dsolution_kwargs(**kwargs):
    """Unpack keyword arguments related to write-solution-in-1D-format."""
    fname = kwargs.get("FileName1D", "solution2d_to_1d.dat")
    dx = kwargs.get("dX", None)
    dy = kwargs.get("dY", None)
    ax = kwargs.get("Direction", None)
    ax_loc = kwargs.get("Locations", None)
    var_dict = {
        "FileName": fname,
        "dX": dx,
        "dY": dy,
        "ax_loc": ax_loc,
        "axis": ax
        }
    return var_dict