public ContextMulticastAction Add(ContextAction ca)
 {
     return(new ContextMulticastAction(_actions.Concat(ca)));
 }
 public ContextMulticastAction <T1, T2> Add(ContextAction <T1, T2> ca)
 {
     return(new ContextMulticastAction <T1, T2>(_actions.Concat(ca)));
 }