/**
  * Clear the entire transaction synchronization state for the current thread: registered
  * synchronizations as well as the various transaction characteristics.
  *
  * @see #clearSynchronization()
  * @see #setCurrentTransactionName
  * @see #setCurrentTransactionReadOnly
  * @see #setCurrentTransactionIsolationLevel
  * @see #setActualTransactionActive
  */
 public static void clear() {
   clearSynchronization();
   setCurrentTransactionName(null);
   setCurrentTransactionReadOnly(false);
   setCurrentTransactionIsolationLevel(null);
   setActualTransactionActive(false);
 }