code: def empty(self, process_tile):
          
          bands = (
              self.output_params["bands"]
              if "bands" in self.output_params
              else PNG_DEFAULT_PROFILE["count"]
          )
          return ma.masked_array(
              data=ma.zeros((bands, ) + process_tile.shape),
              mask=ma.zeros((bands, ) + process_tile.shape),
              dtype=PNG_DEFAULT_PROFILE["dtype"]
          )
docs: Return empty data.
  
          Parameters
          ----------
          process_tile : ``BufferedTile``
              must be member of process ``TilePyramid``
  
          Returns
          -------
          empty data : array
              empty array with data type given in output parameters