static void Check(string input, string expected)
{
var tokens = Tokenize(input);
var inputTree = CreateInMemoryModel(tokens);
var calculator = new VariableCalculator();
var underTest = calculator.Simplify(inputTree);
var asString = new FormattingExpressionVisitor().Format(underTest);
asString.Should().Be(expected);
}
static void Check(string input, string expected)
{
var tokens = Tokenize(input);
var inputTree = CreateInMemoryModel(tokens);
var mover = new AdditionAndSubtractionMover();
var underTest = mover.Simplify(inputTree);
var asString = new FormattingExpressionVisitor().Format(underTest);
asString.Should().Be(expected);
}