code: public static BoundingBox getBoundingBox(Tile upperLeft, Tile lowerRight) {
          BoundingBox ul = upperLeft.getBoundingBox();
          BoundingBox lr = lowerRight.getBoundingBox();
          return ul.extendBoundingBox(lr);
      }
docs: Return the BoundingBox of a rectangle of tiles defined by upper left and lower right tile.
  
  @param upperLeft  tile in upper left corner.
  @param lowerRight tile in lower right corner.
  @return BoundingBox defined by the area around upperLeft and lowerRight Tile.