question: returns the arbitrary string provided by the client associated with this subscription that is delivered to the target address with each notification or null for none . concode_field_sep Lock lock concode_elem_sep String topicId concode_elem_sep String DEFAULT_DATA_STORE_ID concode_elem_sep String clientToken concode_elem_sep UnparsedNotificationCallback notificationCallback concode_elem_sep Long expiration concode_elem_sep long serialVersionUID concode_elem_sep String id concode_field_sep UnparsedNotificationCallback getNotificationCallback concode_elem_sep String getTopicId concode_elem_sep Long getExpiration concode_elem_sep int hashCode concode_elem_sep boolean equals concode_elem_sep DataStore<StoredChannel> getDefaultDataStore concode_elem_sep StoredChannel setClientToken concode_elem_sep String getId concode_elem_sep String toString concode_elem_sep StoredChannel store concode_elem_sep StoredChannel store concode_elem_sep StoredChannel setExpiration concode_elem_sep StoredChannel setTopicId
target: String function ( ) { lock . lock ( ) ; try { return clientToken ; } finally { lock . unlock ( ) ; } }