@Nullable
  public final PsiFileSystemItem getProjectBasedir() {
    final PsiFileSystemItem basedir = getBasedir().getValue();
    if (basedir != null) {
      return basedir;
    }
    final XmlTag tag = getXmlTag();
    final VirtualFile containingFile = tag.getContainingFile().getOriginalFile().getVirtualFile();
    if (containingFile == null) {
      return null;
    }
    final VirtualFile parent = containingFile.getParent();
    if (parent == null) {
      return null;
    }
    return tag.getManager().findDirectory(parent);
  }
@Nullable
  public final PsiFileSystemItem getProjectBasedir()