Group = function (groupName) {
    // all users in the group
    this.users = {};

    this.groupName = groupName;

    this.excludes = {};
    /**
     * @name Group#now
     * @namespace The now namespace for this particular group. Actions
     * to this namespace affect all users that are members of the
     * group. All functions that are called will be called in the
     * context of each individual user in the group.

     * @example everyone.now.prop = 42;
     * @example everyone.now.func = function () {
     *  console.log('hello!');
     * };
     */
    this.now = Proxy.wrap(this);
    // group scope table
    this.scopeTable = new ScopeTable();
  }
@name Group
@class Represents a group containing some subset of all
     users. Each group has its own {@link Group#now} namespace.
@property {String} groupName The name associated with the group.
@see nowjs#getGroup
@see Group#now