public void AddRange(StiStringCollection strs)
 {
     foreach (string str in strs)
     {
         this.Add(str);
     }
 }
 /// <summary>
 /// Creates a new object that is a copy of the current instance.
 /// </summary>
 /// <returns>A new object that is a copy of this instance.</returns>
 public object Clone()
 {
     lock (List)
     {
         StiStringCollection strs = new StiStringCollection();
         foreach (string str in List)
         {
             strs.Add((string)str.Clone());
         }
         return(strs);
     }
 }