hello world AOP example with logging

book-collection-logging.js

class BookCollection {
  ...
  return this.get({
      isbn: isbn
    }).then(book => {
      Logger.info(`Retrieving book ${isbn} - ${book.name} has been succeed`);
      return book.name;
    }).catch(error => {
        Logger.error(`Retrieving book ${isbn} has been failed.  ${JSON.stringify(error)}`);
        return null;
    });
  ...
}