private boolean checkExpression(@Nullable PsiExpression expression) {
      if (expression == null) {
        return false;
      }
      if (expression instanceof PsiReferenceExpression) {
        if (ignoreReferences) {
          return false;
        }
      }
      else if (expression instanceof PsiPolyadicExpression polyadicExpression) {
        if (ignoreComplexLiterals) {
          return false;
        }
        for (PsiExpression operand : polyadicExpression.getOperands()) {
          if (!checkExpression(operand)) {
            return false;
          }
        }
      }
      return true;
    }
private boolean checkExpression(@Nullable PsiExpression expression)