old_contents: const merge = require('lodash.merge');
  
  const set = (object, property, value) =>
    merge({}, object, { [property]: value });
  
  const logJSON = json => console.log(JSON.stringify(json, null, 2));
  
  const testRegex = (regex, string) => new RegExp(regex).test(string);
  
  module.exports = {
    set,
    logJSON,
    testRegex,
  };
  
new_contents: const merge = require('lodash.merge');
  
  const set = (object, property, value) =>
    merge({}, object, { [property]: value });
  
  const logJSON = json => console.log(JSON.stringify(json, null, 2));
  
  const testRegex = (regex, string) => new RegExp(regex).test(string);
  
  const randomString = length =>
    Math.random()
      .toString(36)
      .substr(2, length);
  
  module.exports = {
    set,
    logJSON,
    testRegex,
    randomString,
  };
  
subject: Implement randomString()