private void PerformToStringTest (CultureInfo culture)
{
// set current culture
Thread.CurrentThread.CurrentCulture = culture;
// perform tests
Assert.AreEqual (GetExpectedToString (culture, sz11_0), sz11_0.ToString (),
"TS#1-" + culture.Name);
Assert.AreEqual (GetExpectedToString (culture, sz0_11), sz0_11.ToString (),
"TS#2-" + culture.Name);
Assert.AreEqual (GetExpectedToString (culture, SizeF.Empty), SizeF.Empty.ToString (),
"TS#3-" + culture.Name);
SizeF size = new SizeF (float.NaN, float.NegativeInfinity);
Assert.AreEqual (GetExpectedToString (culture, size), size.ToString (),
"TS#4-" + culture.Name);
}