Constructor
@param classname[, classname...] {String|String[]}
function(classname) {
    this.base(arguments);
    this.initType();
    var args = qx.lang.Array.fromArguments(arguments);
    var t = this;
    this.__classes = [];
    args.forEach(function(arg) {
      if (qx.lang.Type.isArray(arg)) {
        qx.lang.Array.append(t.__classes, arg);
      } else {
        t.__classes.push(arg); 
      }
    });
    this.set({ include: [], exclude: [] });
  }