- https://javascript.info/import-export
- https://stackoverflow.com/questions/37200080/how-to-export-imported-object-in-es6
export let months = ['Jan', 'Feb', 'Mar','Apr', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
export const MODULES_BECAME_STANDARD_YEAR = 2015;
export function sayHi() { ... }