Notifications

 { 
  
 "id" 
 : 
  
  string 
 
 , 
  
 "topic" 
 : 
  
  string 
 
 , 
  
 "event_types" 
 : 
  
 [ 
  
  string 
 
  
 ], 
  
 "custom_attributes" 
 : 
  
 { 
  
  ( 
 key 
 ) 
 
:  
  string 
 
  
 }, 
  
 "payload_format" 
 : 
  
  string 
 
 , 
  
 "object_name_prefix" 
 : 
  
  string 
 
 , 
  
 "etag" 
 : 
  
  string 
 
 , 
  
 "selfLink" 
 : 
  
  string 
 
 , 
  
 "kind" 
 : 
  
 "storage#notification" 
 }