@Override
  protected void callIsDistributed(TXManagerImpl txMgr) {
    assertTrue(txMgr.isDistributed());
  }
Same tests as that of {@link TXManagerImplJUnitTest} after setting "distributed-transactions"
property to true
geode-core/src/integrationTest/java/org/apache/geode/disttx/DistTXManagerImplJUnitTest.java