public function addColumnFields()
    {
        global $post;
        $screen = get_current_screen();

        if (empty($post->post_type) || $screen->base != 'post') {
            return;
        }

        $modules = array();

        // If manually picked
        if ($newModules = $this->checkIfManuallyPicked($post->ID)) {
            $modules = array_merge($modules, $newModules);
        }

        // If post type
        if ($newModules = $this->checkIfPostType($post->ID)) {
            $modules = array_merge($modules, $newModules);
        }

        // If child
        if ($newModules = $this->checkIfChild($post->ID)) {
            $modules = array_merge($modules, $newModules);
        }

        if (empty($modules)) {
            return false;
        }

        $modules = array_filter($modules, function ($item) {
            return !wp_is_post_revision($item);
        });

        $fields = $this->getColumns($modules);

        if (!empty($fields)) {
            add_meta_box(
                'modularity-mod-posts-expandable-list',
                __('Modularity expandable list column values', 'modularity'),
                array($this, 'columnFieldsMetaBoxContent'),
                null,
                'normal',
                'default',
                array($fields)
            );
        }
    }