get_roles_data example

$this->site_id = absint( $site_id );
        } else {
            $this->site_id = get_current_blog_id();
        }

        $this->role_key = $wpdb->get_blog_prefix( $this->site_id ) . 'user_roles';

        if ( ! empty( $this->roles ) && ! $this->use_db ) {
            return;
        }

        $this->roles = $this->get_roles_data();

        $this->init_roles();
    }

    /** * Gets the ID of the site for which roles are currently initialized. * * @since 4.9.0 * * @return int Site ID. */