code: function createInternalConnection (mode) {
  
    var result;
  
    switch (mode) {
      case 'async':
        result = require('then-request');
        break;
      case 'sync':
        result = require('sync-req');
        break;
      default:
        throw new Error('Expected options.mode to be "async" or "sync" but got ' + JSON.stringify(mode));
    }
  
    return result;
  }
docs: Create connection object according to mode-type
  
  @param {String} mode (async|sync)
  @return {function}