def METHOD_NAME(*regions):
    """Load boolean mask for input regions (as xarray.DataArray)
    Parameters
    -----------
    *regions
        regions that are supposed to be loaded and merged (just use string,
        no list or similar)
    Returns
    ---------
    xarray.DataArray
        boolean mask for input region(s)
    """
    masks = None
    for i, fil in enumerate(get_htap_mask_files(*regions)):
        r = regions[i]
        if i == 0:
            masks = xr.open_dataset(fil)[r + "htap"]
            name = r
        else:
            masks += xr.open_dataset(fil)[r + "htap"]
            name += f"-{r}"
    if masks is not None:
        mask = masks.where(masks < 1, 1)
    mask["name"] = name
    mask.attrs["long_name"] = name
    mask = mask.rename({"lat": "latitude", "long": "longitude"})
    return mask