MaeLyrica/How to write plugins

How to write a plugin for MaeLyrica?
A MaeLyrica plug-in is just a class containing these functions and variables:

virtual short perform(string a, string t); // OPTIONAL virtual CURLcode download(string a, string t); virtual string toProviderCode(string artist, string track) const; virtual bool parse; static const QString rooturl;

TO BE CONTINUED