PrepareHeaderForMatch change in CSVHelper v23

Breaking changes in CSVHelper v23 includes "All delegates now take in a single struct argument." PrepareHeaderForMatch is one of those delegates. I get a compile error "Delegate 'PrepareHeaderForMatch' does not take 2 arguments".

I'm sorry about the basic question, but I am not sure how to fix PrepareHeaderForMatch in my code. I'm sure it's simple, but I cannot find any examples or help yet on the web. Maybe this post will help someone else in the future.

        var csvConfig = new CsvConfiguration(CultureInfo.CurrentCulture)
        { 
            HeaderValidated = null,
            MissingFieldFound = null,
            PrepareHeaderForMatch = (string header, int index) => header.ToLower()   // Match header and property names after converting to lower case
        };

Solution

I've been scratching my head on this one as well. The release notes as you say give no indication how to fix the problem, and the documentation has not been updated. I finally had to view the source code to solve it.

This works:

var csvConfig = new CsvConfiguration(CultureInfo.CurrentCulture)
{ 
    PrepareHeaderForMatch = args => args.Header.ToLowerInvariant()
};

I prefer the new class for the args, but a simple example on a breaking change would have been nice.