C#有些句子看不懂

        #region ICollection 成员        void ICollection.CopyTo(Array array, int index)
        {
            this.list.CopyTo(array, index);
        }         int ICollection.Count
        {
            get
            {
                return this.list.Count;
            }        }        bool ICollection.IsSynchronized
        {
            get { return this.list.IsSynchronized; }
        }        object ICollection.SyncRoot
        {
            get { return this.list.SyncRoot; }
        }        #endregion        #region IEnumerable 成员        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.list.GetEnumerator(); ;
        }        #endregion我想问是不是如果要继承 ICollection这个东西，后面就一定要加上面那段代码呢？好像是吧？