old_contents: var GatewayProcessManager = require(__dirname+'/../process_manager.js');
  
  /**
   * @function startGateway
   * @requires GatewayProcessManager
   * @description Starts gateway processes.
   * @param opts
   */
  
  function startGateway(opts, fn) {
    processManager = new GatewayProcessManager();
    processManager.start(opts, function(err, processes){
      fn(null, processes);
    });
  
  }
  
  module.exports = startGateway;
  
  
new_contents: var GatewayProcessManager = require(__dirname+'/../process_manager.js');
  
  /**
   * @function startGateway
   * @requires GatewayProcessManager
   * @description Starts gateway processes.
   * @param opts
   */
  
  function startGateway(opts) {
    processManager = new GatewayProcessManager();
    processManager.start(opts);
  }
  
  module.exports = startGateway;
  
  
subject: Revert "[CHORE] refactor startGateway function to take callback."