public void WithCorrectArgument_ShouldSetValueField() { var value = "name"; var integerArgument = new StringArgument(value); var field = integerArgument.GetType().GetField("value", BindingFlags.NonPublic | BindingFlags.Instance); var expectedValue = value; var actualValue = (string)field.GetValue(integerArgument); Assert.Equal(expectedValue, actualValue); }