code: function createBackendConnector() {
      var axiosConfig = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : {};
  
      function axiosCall(req) {
          // URL is required
          if (typeof req.url !== 'string') {
              throw new Error('The request URL must be a string. Found ' + _typeof(req.url));
          }
          // http method is required
          if (typeof req.httpMethod !== 'string') {
              throw new Error('The request httpMethod must be a string. Found ' + _typeof(req.httpMethod));
          }
  
          return (0, _axios2.default)(Object.assign(axiosConfig, {
              url: req.url,
              method: req.httpMethod,
              headers: req.headers,
              data: req.data
          })).catch(function (error) {
              throw error.response;
          });
      }
  
      return {
          create: axiosCall,
          read: axiosCall,
          update: axiosCall,
          delete: axiosCall
      };
  }
docs: This is a general backend connector that uses axios to execute API calls.
  It requires a request object with the following attributes:
  
  url:        a string value: required
  httpMethod: a string value. The http method to use (https://github.com/mzabriskie/axios); required
  data:       an object or an array; optional
  headers:    an object of the form { <HeaderName>: <Value> }; optional