public void ShouldDisplayTheCorrectPostfixNotation(string input, string expectedOutput)
{
// ARRANGE
input = Helper.RemoveWhiteSpace(input: input);
IShuntingYard sy = new ShuntingYard(input: input);
sy.ConvertToPostfix();
// ACT
string output = Helper.ConvertToString(input: sy.GetPostfix());
// ASSERT
Assert.Equal(expectedOutput, output);
}