code: public Envelope tileBboxLngLat(int tx, int ty, int zoomLevel) {
          Coordinate topLeft = metersToLngLat(tileTopLeft(tx, ty, zoomLevel));
          Coordinate lowerRight = metersToLngLat(tileTopLeft(tx + 1, ty + 1, zoomLevel));
          Envelope result = new Envelope(topLeft, lowerRight);
          return result;
      }
docs: Returns the EPSG:4326 bounding of the specified tile coordinate
  
  @param tx        The tile x coordinate
  @param ty        The tile y coordinate
  @param zoomLevel The tile zoom level
  @return the EPSG:4326 bounding box