public async Task<Speaker> AddSpeakerAsync(Speaker speaker)
        {
            var response = await httpClient.PostAsJsonAsync("speakers/list", speaker);
            var result = await response.Content.ReadAsAsync<Speaker>();

            return result;
        }
 public async Task UpdateSpeakerAsync(Speaker speaker)
 {
     await httpClient.PutAsJsonAsync("speakers/list", speaker);
 }
 public Speaker AddSpeaker(Speaker speaker)
 {
     throw new NotImplementedException();
 }
 public void UpdateSpeaker(Speaker speaker)
 {
     throw new NotImplementedException();
 }
 private void ExecuteAddCommand(object parameter)
 {
     var speaker = new Speaker();
     _editView.AddNewItem(speaker);
     this.RefreshCommands();
     this.IsDeleteDialogOpen = false;
     this.CurrentState = EDIT_STATE;
 }
 public Speaker AddSpeaker(Speaker speaker)
 {
     throw new NotImplementedException();
 }
 public async Task UpdateSpeakerAsync(Speaker speaker)
 {
     await httpClient.PutAsJsonAsync("speakers/list", speaker);
 }
 public void UpdateSpeaker(Speaker speaker)
 {
     throw new NotImplementedException();
 }