code: function(coords, done) {
  		var tile = document.createElement("img");
  
  		tile.onerror = L.bind(this._tileOnError, this, done, tile);
  
  		if (this.options.crossOrigin) {
  			tile.crossOrigin = "";
  		}
  
  		/*
  		 Alt tag is *set to empty string to keep screen readers from reading URL and for compliance reasons
  		 http://www.w3.org/TR/WCAG20-TECHS/H67
  		 */
  		tile.alt = "";
  
  		var tileUrl = this.getTileUrl(coords);
  
  		if (this.options.useCache) {
  			this._db.get(
  				tileUrl,
  				{ revs_info: true },
  				this._onCacheLookup(tile, tileUrl, done)
  			);
  		} else {
  			// Fall back to standard behaviour
  			tile.onload = L.bind(this._tileOnLoad, this, done, tile);
  			tile.src = tileUrl;
  		}
  
  		return tile;
  	}
docs: Overwrites L.TileLayer.prototype.createTile