SqlMapper.TypeHandler SetValue Function No Execute

Hello! We have a need. You need to give the string a default value when it is null. I rewrote "sqlmapper.typehandler" and found that SetValue was not executed

Here is my code:

/// <summary>
/// string type handler
/// </summary>
public class StringHandler : Dapper.SqlMapper.TypeHandler<string>
{
    public override string Parse(object value)
    {
        return value?.ToString() ?? string.Empty;
    }

    public override void SetValue(IDbDataParameter parameter, string value)
    {
        parameter.Value = value ?? string.Empty;
    }
    
}

No repository file or test is named in the issue. Start by reproducing the provided StringHandler with Dapper.SqlMapper.TypeHandler and trace parameter binding to determine why SetValue is not reached. Done means the reported null-string scenario is understood and covered by a regression test showing the expected parameter value.