Calling the SaveToAsync function threw an exception

[debugCode1024]

Hello, I have some problems during use.
(1) Property Name Key under the same Section is not unique?
(2) Calling the SaveToAsync function threw an exception.
Can you help me with my doubts? thanks

`
var ini = new Ini()
{
new Section("SectionName")
{
new Property("PropertyName_1", "A string value"),
new Property("PropertyName_2", 10),
new Property("PropertyName_2", DateTime.Now) // Property Name Key Not Unique ?
}
};

        string desktopDirectory = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
        string filePath = Path.Combine(desktopDirectory, "TestIni.ini");
        using var writer = new StreamWriter(filePath, false, Encoding.UTF8);
        ini.SaveToAsync(writer); // System.InvalidOperationException : The stream is currently in use by a previous operation on the stream.

`