old_contents: 
  /* jshint esnext: true, asi: true */
  
  exports.print = () => console.log('Hello from jsdb!')
new_contents: 
  /* jshint esnext: true, asi: true */
  
  exports.createDatabase = (name) => console.log(`Create database ${name}`)
  exports.createTable = (name) => console.log(`Create table ${name}`)
  exports.useDatabase = (name) => console.log(`Use database ${name}`)
  exports.saveDatabase = (url) => console.log(`Save database in ${url}`)
  exports.loadDatabase = (url) => console.log(`Load database from ${url}`)
  
subject: Add stub functions