public bool Contains(Announcement value)
 {
     return(List.Contains(value));
 }
 public void Remove(Announcement value)
 {
     List.Remove(value);
 }
 public int IndexOf(Announcement value)
 {
     return(List.IndexOf(value));
 }
 public void Insert(int index, Announcement value)
 {
     List.Insert(index, value);
 }
 public int Add(Announcement value)
 {
     return(List.Add(value));
 }