WP_Site_Health::can_perform_loopback

				'loopback_requests'    => array(
					'label' => __( 'Loopback request' ),
					'test'  => 'loopback_requests',
				),
			),
		);

		// Conditionally include REST rules if the function for it exists.
		if ( function_exists( 'rest_url' ) ) {
			$tests['direct']['rest_availability'] = array(
				'label' => __( 'REST API availability' ),
				'test'  => 'rest_availability',
			);
		}

		/**
		 * Add or modify which site status tests are run on a site.
		 *
		 * The site health is determined by a set of tests based on best practices from
		 * both the WordPress Hosting Team, but also web standards in general.
		 *
		 * Some sites may not have the same requirements, for example the automatic update
		 * checks may be handled by a host, and are therefore disabled in core.
		 * Or maybe you want to introduce a new test, is caching enabled/disabled/stale for example.
		 *
		 * Tests may be added either as direct, or asynchronous ones. Any test that may require some time
		 * to complete should run asynchronously, to avoid extended loading periods within wp-admin.
		 *
		 * @since 5.2.0
		 *
		 * @param array $test_type {
		 *     An associative array, where the `$test_type` is either `direct` or
		 *     `async`, to declare if the test should run via Ajax calls after page load.
		 *
		 *     @type array $identifier {
		 *         `$identifier` should be a unique identifier for the test that should run.
		 *         Plugins and themes are encouraged to prefix test identifiers with their slug
		 *         to avoid any collisions between tests.
		 *
		 *         @type string $label A friendly label for your test to identify it by.
		 *         @type mixed  $test  A callable to perform a direct test, or a string Ajax action to be called
		 *                             to perform an async test.
		 *     }
		 * }
		 */
		$tests = apply_filters( 'site_status_tests', $tests );

		// Ensure that the filtered tests contain the required array keys.
		$tests = array_merge(
			array(