public TXStateProxy internalSuspend() {
    return internalSuspend(false);
  }
If the current thread is in a transaction then internal suspend will cause it to no longer be
in a transaction. The thread can start a new transaction after it internal suspended a
transaction.

@return the state of the transaction or null. to reactivate the suspended transaction.
geode-core/src/main/java/org/apache/geode/internal/cache/TXManagerImpl.java