er, Map} from 'leaflet';

			const grid = new GridLayer({
				attribution: 'Grid Layer'
			});

			grid.createTile = function (coords, done) {
				const tile = document.createElement('div');

				tile.innerHTML = [coords.x, coords.y, coords.z].join(', ');
				tile.style.outline = '1px solid red';
				tile.style.background = 'white';

				// test async
				setTimeout(() => done(null, tile), 500 + Math.random() * 500);

				return tile;
			};

			grid.on('loading', () => console.log('loading'));
			grid.on('l