@Test
  public void testConcurrentCreation() throws Exception {
    invokeAsync(vm0, () -> createPartitionedRegions(prNamePrefix, numberOfRegions));
    invokeAsync(vm1, () -> createPartitionedRegions(prNamePrefix, numberOfRegions));
    invokeAsync(vm2, () -> createPartitionedRegions(prNamePrefix, numberOfRegions));
    invokeAsync(vm3, () -> createPartitionedRegions(prNamePrefix, numberOfRegions));

    awaitAllAsyncInvocations();

    // validating that regions are successfully created
    vm0.invoke(() -> validatePR(prNamePrefix, numberOfRegions));
    vm1.invoke(() -> validatePR(prNamePrefix, numberOfRegions));
    vm2.invoke(() -> validatePR(prNamePrefix, numberOfRegions));
    vm3.invoke(() -> validatePR(prNamePrefix, numberOfRegions));
  }
This test create regions with scope = DISTRIBUTED_NO_ACK and then validating these partition
regions
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/PartitionedRegionCreationDUnitTest.java