public void Except_can_accept_properties()
{
var props = new Properties {
{ "accept", "me" },
{ "reject", "others" },
};
var pp = PropertyProvider.Except(props, "reject");
Assert.True(pp.TryGetProperty("accept", null, out _));
Assert.True(pp.TryGetProperty("Accept", null, out _)); // case insensitive
Assert.False(pp.TryGetProperty("reject", null, out _));
}