private @Nullable Object getSlowData(@NotNull String dataId, @NotNull TreePath path) {
      if (CommonDataKeys.PSI_ELEMENT.is(dataId)) {
        return getElementFromPath(path);
      }
      else if (CommonDataKeys.PSI_FILE.is(dataId)) {
        PsiElement element = getElementFromPath(path);
        return element == null ? null : element.getContainingFile();
      }
      return null;
    }
private @Nullable Object getSlowData(@NotNull String dataId, @NotNull TreePath path)