old_contents: const driver = require('../drivers/' + process.env.IAAS + '/driver');
  
  module.exports = {
  
    _initialized: false,
  
    init: function(callback) {
  
      return driver.init((err) => {
  
        if (err) {
          callback(err);
        }
  
        this._initialized = true;
        callback();
      });
    },
  
    getDriverType: function() {
      return process.env.IAAS;
    },
  
    find: function(callback) {
      return driver.find(callback);
    },
  
    create: function(data) {
      return driver.create(data);
    }
  };
  
new_contents: const driver = require('../drivers/' + process.env.IAAS + '/driver');
  
  module.exports = {
  
    _initialized: false,
  
    init: function(callback) {
  
      return driver.init((err) => {
  
        if (err) {
          return callback(err);
        }
  
        this._initialized = true;
        return callback();
      });
    },
  
    getDriverType: function() {
      return process.env.IAAS;
    },
  
    find: function(callback) {
      return driver.find(callback);
    },
  
    create: function(data) {
      return driver.create(data);
    }
  };
  
subject: Fix error callback with no return