$wp_roles = wp_roles();

			foreach ( $user->caps as $cap => $has ) {
				if ( $has && ! $wp_roles->is_role( $cap ) ) {
					$user_caps[] = $cap;
				}
			}
		}

		return self::get_role_from_caps( array_merge( $role_caps, $user_caps ) );
	}

	/**
	 * Gets all canonical roles of at least the given canonical role capability.
	 *
	 * @example ::get_canonical_roles_of_at_least( 'editor' ) // [ 'administrator', 'editor' ]
	 *
	 * @param string $minimum
	 *
	 * @return string[]
	 */
	public static function get_canonical_roles_of_at_least( $minimum ) {
		$at_least = [];

		foreach ( self::$canonical as $role ) {
			$at_least[] = $role;

			if ( $role === $minimum ) {
				break;
			}
		}

		return $at_least;
	}

	/**
	 * Get all users that have the given canonical role.
	 *
	 * @param string|string[] $canonical
	 * @param array           $additional_args
	 *
	 * @return WP_User[]
	 */
	public static function get_users_with_canonical_role( $canonical, $additional_args = array() ) {

		$canonical = (array) $canonical;

		$roles = array();

		foreach ( wp_roles()->roles as $role => $_ ) {
			if ( in_array( self::get_canonical_role_from_role( $role ), $canonical, true ) ) {
				$roles[] = $role;
			}
		}

		if ( empty( $roles ) ) {
			return array();
		}

		return get_users( array_merge( $additional_args, array( 'role__in' => $roles ) ) );
	}

	/**
	 * Get a list of all of the capabilities that are unique to each role.
	 *
	 * @return array
	 */
	public static function get_unique_capabilities() {
		return array(
			'administrator' => array(
				'activate_plugins',
				'create_users',
				'delete_plugins',
				'delete_themes',
				'delete_users',
				'edit_dashboard',
				'edit_files',
				'edit_plugins',
				'edit_theme_options',
				'edit_themes',
				'edit_users',
				'export',
				'import',
				'install_plugins',
				'install_themes',
				'level_8',
				'level_9',
				'level_10',
				'list_users',
				'manage_options',
				'promote_users',
				'remove_users',
				'switch_themes',
				'unfiltered_upload',
				'update_core',
				'update_plugins',
				'update_themes',
			),
			'editor'        => array(
				'delete_others_pages',
				'delete_others_posts',
				'delete_pages',
				'delete_private_pages',
				'delete_private_posts',
				'delete_published_pages',
				'edit_others_pages',
				'edit_others_posts',
				'edit_pages',
				'edit_private_pages',
				'edit_private_posts',
				'edit_published_pages',
				'level_3',
				'level_4',
				'level_5',
				'level_6',
				'level_7',
				'manage_categories',
				'manage_links',
				'moderate_comments',
				'publish_pages',
				'read_private_pages',
				'read_private_posts',
				'unfiltered_html',
			),
			'author'        => array(
				'delete_published_posts',
				'edit_published_posts',
				'level_2',
				'publish_posts',
				'upload_files',
			),
			'contributor'   => array(
				'delete_posts',
				'edit_posts',
				'level_1',
			),
			'subscriber'    => array(
				'level_0',
				'read',
			),
		);
	}

	/**
	 * Get a list of all of the capabilities each default WordPress role has.
	 *
	 * @return array
	 */
	public static function get_capabilities() {
		return array(
			'administrator' => array(
				'activate_plugins',
				'create_users',
				'delete_others_pages',
				'delete_others_posts',
				'delete_pages',
				'delete_plugins',
				'delete_posts',
				'delete_private_pages',
				'delete_private_posts',
				'delete_published_pages',
				'delete_published_posts',
				'delete_themes',
				'delete_users',
				'edit_dashboard',
				'edit_files',
				'edit_others_pages',
				'edit_others_posts',
				'edit_pages',
				'edit_plugins',
				'edit_posts',
				'edit_private_pages',
				'edit_private_posts',
				'edit_published_pages',
				'edit_published_posts',
				'edit_theme_options',
				'edit_themes',
				'edit_users',
				'export',
				'import',
				'install_plugins',
				'install_themes',
				'level_0',
				'level_1',
				'level_2',
				'level_3',
				'level_4',
				'level_5',
				'level_6',
				'level_7',
				'level_8',
				'level_9',
				'level_10',
				'list_users',
				'manage_categories',
				'manage_links',
				'manage_options',
				'moderate_comments',
				'promote_users',
				'publish_pages',
				'publish_posts',
				'read',
				'read_private_pages',
				'read_private_posts',
				'remove_users',
				'switch_themes',
				'unfiltered_html',
				'unfiltered_upload',
				'update_core',
				'update_plugins',
				'update_themes',
				'upload_files',
			),
			'editor'        => array(
				'delete_others_pages',
				'delete_others_posts',
				'delete_pages',
				'delete_posts',
				'delete_private_pages',
				'delete_private_posts',
				'delete_published_pages',
				'delete_published_posts',
				'edit_others_pages',
				'edit_others_posts',
				'edit_pages',
				'edit_posts',
				'edit_private_pages',
				'edit_private_posts',
				'edit_published_pages',
				'edit_published_posts',
				'level_0',
				'level_1',
				'level_2',
				'level_3',
				'level_4',
				'level_5',
				'level_6',
				'level_7',
				'manage_categories',
				'manage_links',
				'moderate_comments',
				'publish_pages',
				'publish_posts',
				'read',
				'read_private_pages',
				'read_private_posts',
				'unfiltered_html',
				'upload_files',
			),
			'author'        => array(
				'delete_posts',
				'delete_published_posts',
				'edit_posts',
				'edit_published_posts',
				'level_0',
				'level_1',
				'level_2',
				'publish_posts',
				'read',
				'upload_files',
			),
			'contributor'   => array(
				'delete_posts',
				'edit_posts',
				'level_0',
				'level_1',
				'read',
			),
			'subscriber'    => array(
				'level_0',
				'read',
			),
		);
	}
}