code: def get_update_tile(self, params, values):
          
          doglobal, particles = self._update_type(params)
          if doglobal:
              return self.shape.copy()
  
          # 1) store the current parameters of interest
          values0 = self.get_values(params)
          # 2) calculate the current tileset
          tiles0 = [self._tile(n) for n in particles]
  
          # 3) update to newer parameters and calculate tileset
          self.set_values(params, values)
          tiles1 = [self._tile(n) for n in particles]
  
          # 4) revert parameters & return union of all tiles
          self.set_values(params, values0)
          return Tile.boundingtile(tiles0 + tiles1)
docs: Get the amount of support size required for a particular update.