protected static <T extends  PsiElement> void setMirrorIfPresent(@Nullable T stub, @Nullable T mirror) throws InvalidMirrorException {
    if ((stub == null) != (mirror == null)) {
      throw new InvalidMirrorException(stub, mirror);
    }
    else if (stub != null) {
      ((ClsElementImpl)stub).setMirror(SourceTreeToPsiMap.psiToTreeNotNull(mirror));
    }
  }
protected static <T extends  PsiElement> void setMirrorIfPresent(@Nullable T stub, @Nullable T mirror)