public static void registerInterestList() {
    try {
      Region r = cache.getRegion(SEPARATOR + regionName);
      assertNotNull(r);
      r.registerInterest("k1");
      r.registerInterest("k3");
      r.registerInterest("k5");
    } catch (Exception ex) {
      Assert.fail("failed while registering keys", ex);
    }
  }
A helper for creating a subregion, potentially using a package protected method to do so.

@param root the parent region
@param name the name of the subregion to create
@param attrs the attributes used to create the subregion
@param internalArgs if not null, then use the package protected creation mechanism
@return the subregion whose parent is the provided root
@see Region#createSubregion(String, RegionAttributes)
@see LocalRegion#createSubregion(String, RegionAttributes, InternalRegionArguments)
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/ha/CQListGIIDistributedTest.java