code: function postBackApi (processor, acl) {
      return {
          async postBack (args, ctx) {
              if (!apiAuthorizer(args, ctx, acl)) {
                  return null;
              }
  
              const event = RequestsFactories.postBack(args.senderId, args.action, args.data);
  
              return processor.processMessage(event, args.senderId, args.pageId);
          }
      };
  }
docs: @typedef {Object} PostBackAPI
  @typedef {Function} postBack
   
  Create a postback API
  
  @param {{processMessage:Function}} processor - running messaging channel, like Facebook
  @param {string[]|Function} [acl] - limit api to array of groups or use auth function
  @returns {PostBackAPI}
  @example
  const { GraphApi, postBackApi } = require('wingbot');
  
  const api = new GraphApi([
  postBackApi(channel)
  ], {
  appToken: 'API-will-be-accessible-with-this-token-in-Authorization-header'
  })