code: def nside_to_pixel_area(nside):
      
      nside = np.asanyarray(nside, dtype=np.int64)
      _validate_nside(nside)
      npix = 12 * nside * nside
      pixel_area = 4 * math.pi / npix * u.sr
      return pixel_area
docs: Find the area of HEALPix pixels given the pixel dimensions of one of
      the 12 'top-level' HEALPix tiles.
  
      Parameters
      ----------
      nside : int
          The number of pixels on the side of one of the 12 'top-level' HEALPix tiles.
  
      Returns
      -------
      pixel_area : :class:`~astropy.units.Quantity`
          The area of the HEALPix pixels