src/event-driver-hooks.js
async function beforeEachHook(done) {
    browser.__autoStart = browser.__prom = browser.__rejectSerial = browser.__resolveSerial = null;
    done && done();
}
async function beforeEachHook(done) {
    browser.__autoStart = browser.__prom = browser.__rejectSerial = browser.__resolveSerial = null;
    done && done();
}
async function beforeEachHook ( done ) { browser . __autoStart = browser . __prom = browser . __rejectSerial = browser . __resolveSerial = null ; done && done ( ) ; }
run before each test, reset browser status
@return promise
run before each test reset browser status