Function assertService

src/element-service.js:149–162

* Throws user error if `service` is null. * @param {object} service * @param {string} id * @param {string} extension * @return {!Object} * @private * @closurePrimitive {asserts.matchesReturn}

(service, id, extension)

 * @closurePrimitive {asserts.matchesReturn}
 */
function assertService(service, id, extension) {
  return /** @type {!Object} */ (
    userAssert(
      service,
      'Service %s was requested to be provided through %s, ' +
        'but %s is not loaded in the current page. To fix this ' +
        'problem load the JavaScript file for %s in this page.',
      id,
      extension,
      extension,
      extension
    )
  );
}

/**
 * Returns the promise for service with `id` on the given window if available.