question: ObjectStreamField [ ] fields ( ) { if ( fields == null ) { Class < ? > forCl = forClass ( ) ; if ( forCl != null && isSerializable ( ) && ! forCl . isArray ( ) ) { buildFieldDescriptors ( forCl . getDeclaredFields ( ) ) ; } else { setFields ( NO_FIELDS ) ; } } return fields ; }
target:  Returns the collection of field descriptors for the fields of the corresponding class