static @Nullable PsiExpression getInstanceOfOperand(PsiElement position) {
    PsiElement parent = position.getParent();
    while (parent instanceof PsiJavaCodeReferenceElement || parent instanceof PsiTypeElement) {
      parent = parent.getParent();
    }
    if (parent instanceof PsiInstanceOfExpression) {
      return ((PsiInstanceOfExpression)parent).getOperand();
    }
    return null;
  }
static @Nullable PsiExpression getInstanceOfOperand(PsiElement position)