@Nullable
    <T extends PsiElement> T show(@DialogTitle @NotNull String errorTitle,
                                  @NonNls @Nullable String selectedItem,
                                  @NotNull FileCreator<T> creator);
@Nullable
    <T extends PsiElement> T show(@DialogTitle @NotNull String errorTitle,
                                  @NonNls @Nullable String selectedItem,
                                  @NotNull FileCreator<T> creator)