how to test this kind of function

[takoya]

I'm a beginner of cppunit

I don't know how to test such kind of function

bool A::get(string a, string b)
{
    if(another.search(a).get()==b)
        return true;
    else return false;
}

Third Another::search(string a)
{
}
This function returns an instance of class Third
another is an instance of Another and it is global

How do I use CPPUNIT_ASSERT in this case?