function loadTMXLevel(levelId, container, flatten, setViewportBounds) {
	const level = levels[levelId];
	// reset the GUID generator
	// and pass the level id as parameter
	resetGUID(levelId, level.nextobjectid);

	// Tiled use 0,0 anchor coordinates
	container.anchorPoint.set(0, 0);

	// add all level elements to the target container
	level.addTo(container, flatten, setViewportBounds);
}
Load a TMX level
@name loadTMXLevel
@memberof level
@private
@param {string} levelId - level id
@param {Container} container - target container
@param {boolean} [flatten=true] - if true, flatten all objects into the given container
@param {boolean} [setViewportBounds=false] - if true, set the viewport bounds to the map size, this should be set to true especially if adding a level to the game world container.
@ignore