code: function getItem( key ) {
        const item = backend.getItem( `${namespace}.${key}` );
        return item && JSON.parse( item );
     }
docs: ///////////////////////////////////////////////////////////////////////////////////////////////////////// 
  Retrieves a `value` by `key` from the store. JSON deserialization will automatically be applied.
  
  @param {String} key
  the key of the item to retrieve (without namespace prefix)
  
  @return {*}
  the value or `null` if it doesn't exist in the store
  
  @memberof StorageApi