constructor(world, bounds, max_objects = 4, max_levels = 4, level = 0) {
		this.world = world;
		this.bounds = bounds;

		this.max_objects = max_objects;
		this.max_levels = max_levels;

		this.level = level;

		this.objects = [];
		this.nodes = [];
	}
@param {World} world - the physic world this QuadTree belongs to
@param {Bounds} bounds - bounds of the node
@param {number} [max_objects=4] - max objects a node can hold before splitting into 4 subnodes
@param {number} [max_levels=4] - total max levels inside root Quadtree
@param {number} [level] - deepth level, required for subnodes