@ApiStatus.Experimental
  public static void setNonPhysicalFileDeleteHandler(@NotNull PsiFile file, @NotNull Consumer<@NotNull PsiFile> handler) {
    if (file.isPhysical()) {
      throw new IllegalArgumentException();
    }
    file.putUserData(NON_PHYSICAL_FILE_DELETE_HANDLER, handler);
  }
@ApiStatus.Experimental
  public static void setNonPhysicalFileDeleteHandler(@NotNull PsiFile file, @NotNull Consumer<@NotNull PsiFile> handler)