public void Remove(DerivativeSecurityListRequestUnderlyingSecurityAltID item)
 {
     if (_al != null)
     {
         _al.Remove(item);
     }
 }
 public void Add(DerivativeSecurityListRequestUnderlyingSecurityAltID item)
 {
     if (_al == null)
     {
         _al = new ArrayList();
     }
     _al.Add(item);
     _last = item;
 }