Gtk::TreeModelColumn<bool> gain;
Gtk::TreeModelColumn<bool> gain_relative;
Gtk::TreeModelColumn<bool> mute;
Gtk::TreeModelColumn<bool> solo;
Gtk::TreeModelColumn<bool> record;
Gtk::TreeModelColumn<bool> gain;
Gtk::TreeModelColumn<bool> gain_relative;
Gtk::TreeModelColumn<bool> mute;
Gtk::TreeModelColumn<bool> solo;
Gtk::TreeModelColumn<bool> record;