index.js
function initialize(server, callback) {
		source = new Backend(server, options);
		source.initialize(callback);
	}
function initialize(server, callback) {
		source = new Backend(server, options);
		source.initialize(callback);
	}
function initialize ( server , callback ) { source = new Backend ( server , options ) ; source . initialize ( callback ) ; }
Initializes the mapnik datasource.

@param {TileServer} server
@param {function} callback(err, fn)
@return {void}
Initializes the mapnik datasource .