public void Allow_UseAddMethod_AddedValueCanBeRetrievedUsingProperty()
{
_headers.TryAddWithoutValidation("Allow", ",custom1, custom2, custom3,");
Assert.Equal(3, _headers.Allow.Count);
Assert.Equal(3, _headers.GetValues("Allow").Count());
Assert.Equal("custom1", _headers.Allow.ElementAt(0));
Assert.Equal("custom2", _headers.Allow.ElementAt(1));
Assert.Equal("custom3", _headers.Allow.ElementAt(2));
_headers.Allow.Clear();
Assert.Equal(0, _headers.Allow.Count);
Assert.False(_headers.Contains("Allow"));
}