public void SolveTest()
 {
     Expression operand1 = new ValueExpression(2); // TODO: Initialize to an appropriate value
     Expression operand2 = new ValueExpression(3); // TODO: Initialize to an appropriate value
     PowerExpression target = new PowerExpression(operand1, operand2); // TODO: Initialize to an appropriate value
     Expression expected = new ValueExpression(8); // TODO: Initialize to an appropriate value
     Expression actual;
     actual = target.Solve();
     Assert.AreEqual<ValueExpression>((ValueExpression)expected , (ValueExpression)actual);
 }