code: def level_to_nside(level):
      
      level = np.asarray(level, dtype=np.int64)
  
      _validate_level(level)
      return 2 ** level
docs: Find the pixel dimensions of the top-level HEALPix tiles.
  
      This is given by ``nside = 2**level``.
  
      Parameters
      ----------
      level : int
          The resolution level
  
      Returns
      -------
      nside : int
          The number of pixels on the side of one of the 12 'top-level' HEALPix tiles.