index.js
function (callback) {
            var mapName;

            for (mapName in this.maps) {
                if (this.maps.hasOwnProperty(mapName)) {
                    callback.call(this, this.maps[mapName], mapName);
                }
            }
        }
function (callback) {
            var mapName;

            for (mapName in this.maps) {
                if (this.maps.hasOwnProperty(mapName)) {
                    callback.call(this, this.maps[mapName], mapName);
                }
            }
        }
function ( callback ) { var mapName ; for ( mapName in this . maps ) { if ( this . maps . hasOwnProperty ( mapName ) ) { callback . call ( this , this . maps [ mapName ] , mapName ) ; } } }
Iterates through all the maps

@private
@param {Function(Object[], String)} callback
Iterates through all the maps