code: function (coords) {
  
  		var map = this._map,
  		    tileSize = this.getTileSize(),
  
  		    nwPoint = coords.scaleBy(tileSize),
  		    sePoint = nwPoint.add(tileSize),
  
  		    nw = map.wrapLatLng(map.unproject(nwPoint, coords.z)),
  		    se = map.wrapLatLng(map.unproject(sePoint, coords.z));
  
  		return new L.LatLngBounds(nw, se);
  	}
docs: converts tile coordinates to its geographical bounds