/**
 * Gets executed before test execution begins. At this point you can access to all global
 * variables like `browser`. It is the perfect place to define custom commands.
 * @param {Array.<Object>} capabilities list of capabilities details
 * @param {Array.<String>} specs        List of spec file paths that are to be run
 * @param {Object}         browser      instance of created browser/device session
 */
export default function (capabilities: object[], specs: string[], browser: object): Promise<void>;