Method add4

tests/test_methods_and_attributes.cpp:49–49

passing by const reference

    void add2(ExampleMandA &other) { value += other.value; }        // passing by reference
    void add3(const ExampleMandA &other) { value += other.value; }  // passing by const reference
    void add4(ExampleMandA *other) { value += other->value; }       // passing by pointer
    void add5(const ExampleMandA *other) { value += other->value; } // passing by const pointer

    void add6(int other) { value += other; }        // passing by value