src/js/core/page.js
function hasChanged(ctx) {
    console.log('page has changed', ctx); // eslint-disable-line no-console
    setState(ctx);

    if (!started) {
        // Notify that gitbook is ready
        started = true;
        events.trigger('start', ctx.config.pluginsConfig);
    }

    events.trigger('page.change');
}
function hasChanged(ctx) {
    console.log('page has changed', ctx); // eslint-disable-line no-console
    setState(ctx);

    if (!started) {
        // Notify that gitbook is ready
        started = true;
        events.trigger('start', ctx.config.pluginsConfig);
    }

    events.trigger('page.change');
}
/*
Signal that page has changed, this function must be called by
themes after page is loaded and when navigation changed