Method add

prefsKeybinding.js:403–411

(combo)

    }

    add(combo) {
        const [found, _] = this.find(combo);
        if (found)
            return;
        this.combos.append(combo);
        if (!combo.disabled) {
            this._store();
        }
    }

    remove(combo) {
        const [found, pos] = this.find(combo);