text: import uuid from 'uuid/v4';
  
  const getSessionKey = key => {
      const storedValue = sessionStorage.getItem(key);
  
      if (storedValue) {
          return storedValue;
      }
  
      const newValue = uuid();
      sessionStorage.setItem(key, newValue);
      return newValue;
  };
  
  export default (key = 'trackingVisitorSession') => () => ({session: getSessionKey(key)});
  