public void StandartConstuctorTest()
 {
     op = new Operand();
     Assert.AreEqual(0, op.Result());
 }
 private static IParsingTreeVertex WorkRealSentence(String sentence)
 {
     int number = 0;
     ParsingStack stack = new ParsingStack();
     Operation result = GetNeededOperation(sentence[1]);
     stack.Push(result);
     sentence = sentence.Remove(0, 3);
     while (sentence.Length != 0)
     {
         try
         {
             while (stack.Top().GetCount() == 2)
             {
                 stack.Pop();
             }
         }
         catch(StackNullExeption)
         {
             return result;
         }
         switch (sentence[0])
         {
             case '+':
             case '-':
             case '*':
             case '/':
             {
                 Operation pushed = GetNeededOperation(sentence[0]);
                 AddChildToStackTop(stack.Top(), pushed);
                 stack.Push(pushed);
                 sentence = sentence.Remove(0, 1);
                 break;
             }
             case '0':
             case '1':
             case '2':
             case '3':
             case '4':
             case '5':
             case '6':
             case '7':
             case '8':
             case '9':
             {
                 number = ConvertToInt(ref sentence);
                 Operand added = new Operand(number);
                 number = 0;
                 AddChildToStackTop(stack.Top(), added);
                 break;
             }
             case '(':
             case ')':
             case ' ':
             {
                 sentence = sentence.Remove(0, 1);
                 break;
             }
             default:
             {
                 throw new WrongInputException("Unexpected character \"" + sentence[0] + '\n');
             }
         }
     }
     throw new ConstructorFailException("Didn't manage...");
 }
 public void ConstructorByValueTest()
 {
     op = new Operand(10);
     Assert.AreEqual(10, op.Result());
 }