C++ ----- Song.h is given please help me with Song.cpp

Class Song

You will code your own Song class, so you can add Songs to your playlist. A Song stores the following information (private member variables):

std::string title_;

std::string author_;

std::string album_;

And the following operations (public member functions)

Song();

Song(const std::string& title, const std::string& author = "", const std::string& album = "");

void setTitle(std::string title);

void setAuthor(std::string author);

void setAlbum(std::string album);

std::string getTitle() const;

std::string getAuthor() const;

std::string getAlbum() const;

friend bool operator==(const Song& lhs, const Song& rhs);