private static boolean isBetterWithCharAt(final @NotNull PsiMethodCallExpression call) {
      final PsiExpression[] args = call.getArgumentList().getExpressions();
      final PsiElementFactory factory = JavaPsiFacade.getElementFactory(call.getProject());

      final PsiExpression one = factory.createExpressionFromText("1", null);
      final boolean diffByOne = ExpressionUtils.isDifference(args[0], args[1], one);
      if (!diffByOne) return false;

      return !ExpressionUtils.isConversionToStringNecessary(call, false);
    }
private static boolean isBetterWithCharAt(final @NotNull PsiMethodCallExpression call)