a small and tiny loger util. easy to understand and use.
import Loger from 'tinyLoger';
// set output level(optional)
Loger.setLogLevel(Loger.ERROR);
// set output prefix(optional)
let loger = Loger.getLoger('login process: ');
// enjoy.
loger.info('login successfull.');
loger.error('login fails.');
loger.warn('usename is required.');