public MessageSendRequest(string messageText, string[] gamertags)
 {
     Header = new MessageSendHeader()
     {
         Recipients = Array.ConvertAll(gamertags, x =>
                                       new GamertagRecipient()
         {
             Gamertag = x
         })
     };
     MessageText = messageText;
 }
 public MessageSendRequest(string messageText, ulong[] xuids)
 {
     Header = new MessageSendHeader()
     {
         Recipients = Array.ConvertAll(xuids, x =>
                                       new XuidRecipient()
         {
             Xuid = x.ToString()
         })
     };
     MessageText = messageText;
 }