private async Task getIslandList()
        {
            var islands = await App.Repository.Island.GetAsync();

            MasterIslandList.Clear();
            foreach (var island in islands)
            {
                MasterIslandList.Add(island);
            }
        }
 public void UpdateIslands(string atollid)
 {
     Islands.Clear();
     if (!string.IsNullOrEmpty(atollid))
     {
         string[] parameters = atollid.Split(new char[] { ' ' },
                                             StringSplitOptions.RemoveEmptyEntries);
         var resultlist = MasterIslandList
                          .Where(island => parameters
                                 .Any(parameter =>
                                      island.Atoll.AtollId.ToString().StartsWith(parameter)))
         ;
         foreach (var island in resultlist)
         {
             Islands.Add(island);
         }
     }
 }