docs: protected boolean prePrepare() {
          if (tc.isEntryEnabled())
              Tr.entry(tc, "prePrepare");
  
          //
          // Cancel timeout prior to completion phase
          //
          cancelAlarms();
  
          //
          // Inform the Synchronisations we are about to complete
          //
          if (!_rollbackOnly) {
              if (_syncs != null) {
                  _syncs.distributeBefore();
              }
          }
  
          if (tc.isEntryEnabled())
              Tr.exit(tc, "prePrepare", !_rollbackOnly);
          return !_rollbackOnly;
      }