@Nullable
  public static PsiElement nearestLeftSibling(PsiElement elem) {
    elem = elem.getPrevSibling();
    while (elem != null &&
           (elem instanceof PsiWhiteSpace ||
            elem instanceof PsiComment ||
            GroovyTokenTypes.mNLS.equals(elem.getNode().getElementType()))) {
      elem = elem.getPrevSibling();
    }
    return elem;
  }
@Nullable
  public static PsiElement nearestLeftSibling(PsiElement elem)