protected @Nullable Icon computeBaseIcon(@Iconable.IconFlags int flags) {
    Icon baseIcon = isVisibilitySupported() ? getAdjustedBaseIcon(getBaseIcon(), flags) : getBaseIcon();

    // to prevent blinking, base icon should be created with the layers
    if (baseIcon != null && this instanceof PsiElement) {
      PsiFile file = ((PsiElement)this).getContainingFile();
      if (file != null) {
        return IconManager.getInstance().createLayeredIcon(file, baseIcon, flags);
      }
    }
    return baseIcon;
  }
protected @Nullable Icon computeBaseIcon(@Iconable.IconFlags int flags)