code: def load_background_sky_map(background_sky_map_path, background_sky_map_hdu, pixel_scale):
      
      if background_sky_map_path is not None:
          return ScaledSquarePixelArray.from_fits_with_pixel_scale(file_path=background_sky_map_path,
                                                                   hdu=background_sky_map_hdu, pixel_scale=pixel_scale)
      else:
          return None
docs: Factory for loading the background sky from a .fits file.
  
      Parameters
      ----------
      background_sky_map_path : str
          The path to the background_sky_map .fits file containing the background sky map \
          (e.g. '/path/to/background_sky_map.fits').
      background_sky_map_hdu : int
          The hdu the background_sky_map is contained in the .fits file specified by *background_sky_map_path*.
      pixel_scale : float
          The size of each pixel in arc seconds.