private File newFolder(String folder) {
    try {
      return temporaryFolder.newFolder(folder);
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  }
Regression test for TRAC #41770: ConcurrentRegionOperationsJUnitTest fails with duplicate
create in an oplog
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/DiskRegionJUnitTest.java