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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def latitude_from_cross_section(cross):
 """Calculate the latitude of points in a cross-section. Parameters cross : `xarray.DataArray` The input DataArray of a cross-section from which to obtain latitudes. Returns ------- latitude : `xarray.DataArray` Latitude of points """

    y = cross.metpy.y
    if CFConventionHandler.check_axis(y, 'lat'):
        return y
    else:
        import cartopy.crs as ccrs
        latitude = ccrs.Geodetic().transform_points(cross.metpy.cartopy_crs,
                                                    cross.metpy.x.values,
                                                    y.values)[..., 1]
        latitude = xr.DataArray(latitude, coords=y.coords, dims=y.dims,
                                attrs={'units': 'degrees_north'})
        return latitude