public void AppendChild(FragmentControlProvider newChild) { if (newChild == null) { throw new ArgumentNullException("newChild"); } if (!newChild.Navigation.IsCleared()) { RaiseNewChildIsClearedError(newChild); } if (newChild is FragmentProviderWrapper) { _chainCustoms.AppendToEnd(newChild); } else { _chainWinforms.AppendToEnd(newChild); } newChild.Navigation.Parent = this.Provider; }