code: function(session, args, callback) {
  
          // Parse the arguments using optimist
          var argv = optimist.parse(args);
  
          // Update the environment to indicate who the specified user now is
          session.env('me', argv._[0] || 'unknown');
  
          // The callback always needs to be invoked to finish the command
          return callback();
      }
docs: The function that actually invokes the command. Optimist is being used here to parse the array arguments that were provided to your command, however you can use whatever utility you want