two issues about config remote

Q1: Hereafter code produce two remote sections in the git config file.

Console.WriteLine(GlobalSettings.Version); //{0.22.0-8daef23-785d8c4 (x86 - Threads, Https)}

using (var repo = new Repository(Repository.Init(".\\test.git", true)))
{
    repo.Network.Remotes.Add("origin", @"https://github.com/libgit2/libgit2sharp.git");
}
var config = File.ReadAllText(@".\\test.git\\config");
Console.Write(config);
/*
[remote "origin"]
    url = https://github.com/libgit2/libgit2sharp.git
[remote "origin"]
    fetch = +refs/heads/*:refs/remotes/origin/*
*/

Q2: How to set a remote as mirror. I think there are no API consider about this.

[remote "origin"]
    url = https://github.com/libgit2/libgit2sharp.git
    fetch = +refs/*:refs/*
    mirror = true

Start with the Repository.Init and repo.Network.Remotes.Add calls shown in the issue, then inspect the remote configuration-writing path and related API. Reproduce the generated config and determine how remote sections are serialized; done means the duplicate-section behavior is addressed and the requested mirror configuration question has a defined API outcome.