public void MathExpressionParser_Tokens_Must_Be_In_Postfix_Notation()
{
TokenStream stream = new TokenStream(Enumerable.Empty<Token>(), TokenNotation.Infix);
MathExpressionParser parser = new MathExpressionParser();
var exception = Assert.Throws<MathExpressionException>(() => parser.Parse(stream));
Assert.AreEqual("Tokens are not in postfix notation.", exception.Details);
}