public void MathExpressionParser_No_Tokens_In_Stream_Returns_ConstantExpression()
{
TokenStream stream = new TokenStream(Enumerable.Empty<Token>(), TokenNotation.Postfix);
MathExpressionParser parser = new MathExpressionParser();
MathExpression expression = parser.Parse(stream);
Assert.IsNotNull(expression);
Assert.IsInstanceOf<NumericExpression>(expression);
Assert.AreEqual(0D, ((NumericExpression)expression).Value);
}