public void TestGetOfficeSymbol()
{
var instance = new TestDocument();
Assert.IsNull(configuration.GetOfficeSymbol(instance));
configuration.HasOfficeSymbol(x => x.OfficeSymbol);
Assert.IsNull(configuration.GetOfficeSymbol(instance));
instance.OfficeSymbol = "symbol";
Assert.AreEqual(instance.OfficeSymbol, configuration.GetOfficeSymbol(instance));
}