pusher.js

    this.bind('pusher_internal:member_added', function(data){
        var timeoutMember = this.members.get(data.user_id);

        if(timeoutMember && timeoutMember.info.timeoutID){ // The member is present with a timeout
          clearTimeout(timeoutMember.info.timeoutID);
        }else{
          var member = this.members.add(data.user_id, data.user_info);
          this.dispatch_with_all('pusher:member_added', member);
        }
    }.scopedTo(this))

    this.bind('pusher_internal:member_removed', function(data){
        var that = this;
        var member = this.members.remove(data.user_id); // temporally removing

        member.info.timeoutID = setTimeout(function(){
            var member = that.members.remove(data.user_id);
            if (member) {
              that.dispatch_with_all('pusher:member_removed', member);
            }
          }, 10000);

        // Adding again with the timeout attribute
        this.members.add(member.id, member.info);
    }.scopedTo(this))
  },