code: def level_ipix_to_uniq(level, ipix):
      
      level = np.asarray(level, dtype=np.int64)
      ipix = np.asarray(ipix, dtype=np.int64)
  
      _validate_level(level)
      _validate_npix(level, ipix)
  
      return ipix + (1 << 2*(level + 1))
docs: Convert a level and HEALPix index into a uniq number representing the cell.
  
      This function is the inverse of `uniq_to_level_ipix`.
  
      Parameters
      ----------
      level : int
          The level of the HEALPix cell
      ipix : int
          The index of the HEALPix cell
  
      Returns
      -------
      uniq : int
          The uniq number representing the HEALPix cell.