public void Subtract_SuccessfullySubtracts_Two_ConstantIntegers_Test()
{
//Arrange
var subtractExpression =
new Subtract <int, IContext>(new ConstantInteger <IContext>(2), new ConstantInteger <IContext>(1));
//Act
var sut = subtractExpression.Interpret(_context);
//Assert
Assert.Equal(1, sut);
}