code: def get_pixel_size_from_nside(nside):
      
      order = int(np.log2(nside))
      if order < 0 or order > 13:
          raise ValueError('HEALPix order must be between 0 to 13 %i' % order)
  
      return HPX_ORDER_TO_PIXSIZE[order]
docs: Returns an estimate of the pixel size from the HEALPix nside coordinate
  
      This just uses a lookup table to provide a nice round number for each
      HEALPix order.