How to use the salem.gis.check_crs function in salem

warnings.filterwarnings("ignore", message=mess)
                    try:
                        data = imresize(data.filled(np.NaN),
                                        (self.grid.ny, self.grid.nx),
                                        order=interp, mode='edge',
                                        anti_aliasing=True)
                    except RuntimeError:
                        # For some order anti_aliasing doesnt work with 'edge'
                        data = imresize(data.filled(np.NaN),
                                        (self.grid.ny, self.grid.nx),
                                        order=interp, mode='edge',
                                        anti_aliasing=False)

            return data

        crs = gis.check_crs(crs, raise_on_error=True)
        if isinstance(crs, Grid):
            # Remap
            if overplot:
                data = self.grid.map_gridded_data(data, crs, interp=interp,
                                                  out=self.data)
            else:
                data = self.grid.map_gridded_data(data, crs, interp=interp)
        else:
            raise ValueError('crs should be a grid, not a proj')

        return data

def _salem_grid_from_dataset(ds):
    """Seek for coordinates that Salem might have created.

    Current convention: x_coord, y_coord, pyproj_srs as attribute
    """


    # Projection
    try:
        proj = ds.pyproj_srs
    except AttributeError:
        proj = None
    proj = gis.check_crs(proj)
    if proj is None:
        return None

    # Do we have some standard names as variable?
    vns = ds.variables.keys()
    xc = utils.str_in_list(vns, utils.valid_names['x_dim'])
    yc = utils.str_in_list(vns, utils.valid_names['y_dim'])

    # Sometimes there are more than one coordinates, one of which might have
    # more dims (e.g. lons in WRF files): take the first one with ndim = 1:
    x = None
    for xp in xc:
        if len(ds.variables[xp].shape) == 1:
            x = xp
    y = None
    for yp in yc:

kwargs : **
          any keyword accepted by motionless.CenterMap (e.g. `key` for the API)

        Notes
        -----
        To obtain the exact domain specified in `x` and `y` you may have to
        play with the `size_x` and `size_y` kwargs.
        """

        global API_KEY

        if 'zoom' in kwargs or 'center_ll' in kwargs:
            raise ValueError('incompatible kwargs.')

        # Transform to lonlat
        crs = gis.check_crs(crs)
        if isinstance(crs, pyproj.Proj):
            lon, lat = gis.transform_proj(crs, wgs84, x, y)
        elif isinstance(crs, Grid):
            lon, lat = crs.ij_to_crs(x, y, crs=wgs84)
        else:
            raise NotImplementedError()

        # surely not the smartest way to do but should be enough for now
        mc = (np.mean(lon), np.mean(lat))
        zoom = 20
        while zoom >= 0:
            grid = gis.googlestatic_mercator_grid(center_ll=mc, nx=size_x,
                                                  ny=size_y, zoom=zoom,
                                                  scale=scale)
            dx, dy = grid.transform(lon, lat, maskout=True)
            if np.any(dx.mask):

elif proj_id == 2:
        # Polar stereo
        p4 = '+proj=stere +lat_ts={lat_1} +lon_0={lon_0} +lat_0=90.0' \
             '+x_0=0 +y_0=0 +a=6370000 +b=6370000'
        p4 = p4.format(**pargs)
    elif proj_id == 3:
        # Mercator
        p4 = '+proj=merc +lat_ts={lat_1} ' \
             '+lon_0={center_lon} ' \
             '+x_0=0 +y_0=0 +a=6370000 +b=6370000'
        p4 = p4.format(**pargs)
    else:
        raise NotImplementedError('WRF proj not implemented yet: '
                                  '{}'.format(proj_id))

    proj = gis.check_crs(p4)
    if proj is None:
        raise RuntimeError('WRF proj not understood: {}'.format(p4))

    # Here we have to accept xarray and netCDF4 datasets
    try:
        nx = len(ds.dimensions['west_east'])
        ny = len(ds.dimensions['south_north'])
    except AttributeError:
        # maybe an xarray dataset
        nx = ds.dims['west_east']
        ny = ds.dims['south_north']
    if hasattr(ds, 'PROJ_ENVI_STRING'):
        # HAR
        x0 = ds['west_east'][0]
        y0 = ds['south_north'][0]
    else:

# Lambert
        p4 = '+proj=lcc +lat_1={lat_1} +lat_2={lat_2} ' \
             '+lat_0={lat_0} +lon_0={lon_0} ' \
             '+x_0=0 +y_0=0 +a=6370000 +b=6370000'
        p4 = p4.format(**pargs)
    elif proj_id == 3:
        # Mercator
        p4 = '+proj=merc +lat_ts={lat_1} ' \
             '+lon_0={center_lon} ' \
             '+x_0=0 +y_0=0 +a=6370000 +b=6370000'
        p4 = p4.format(**pargs)
    else:
        raise NotImplementedError('WRF proj not implemented: '
                                  '{}'.format(proj_id))

    proj = gis.check_crs(p4)
    if proj is None:
        raise RuntimeError('WRF proj not understood: {}'.format(p4))

    # Here we have to accept xarray's datasets too
    try:
        nx = len(nc.dimensions['west_east'])
        ny = len(nc.dimensions['south_north'])
    except AttributeError:
        # maybe an xarray dataset
        nx = nc.dims['west_east']
        ny = nc.dims['south_north']
    if hasattr(nc, 'PROJ_ENVI_STRING'):
        # HAR
        x0 = nc.GRID_X00
        y0 = nc.GRID_Y00
    else: