private static boolean isItself(@Nullable PsiExpression left, @Nullable PsiExpression right) {
    return left != null && right != null &&
           EquivalenceChecker.getCanonicalPsiEquivalence().expressionsAreEquivalent(left, right) &&
           !SideEffectChecker.mayHaveSideEffects(left);
  }
private static boolean isItself(@Nullable PsiExpression left, @Nullable PsiExpression right)