@Override
      public Object call() throws Exception {
        Region r = getRootRegion().getSubregion(regionName);
        Map<Integer, String> temp = new HashMap<>();
        for (int i = rng.start; i < rng.end; i++) {
          Integer k = i;
          temp.put(k, "value-" + i);
        }
        try {
          r.putAll(temp);
          if (catchServerException || catchLowMemoryException) {
            fail("An expected ResourceException was not thrown");
          }
          for (Map.Entry<Integer, String> me : temp.entrySet()) {
            assertEquals(me.getValue(), r.get(me.getKey()));
          }
        } catch (ServerOperationException ex) {
          if (!catchServerException) {
            Assert.fail("Unexpected exception: ", ex);
          }
          if (!(ex.getCause() instanceof LowMemoryException)) {
            Assert.fail("Unexpected exception: ", ex);
          }
          for (Integer me : temp.keySet()) {
            assertFalse("Key " + me + " should not exist", r.containsKey(me));
          }
        } catch (LowMemoryException low) {
          LogWriterUtils.getLogWriter().info("Caught LowMemoryException", low);
          if (!catchLowMemoryException) {
            Assert.fail("Unexpected exception: ", low);
          }
          for (Integer me : temp.keySet()) {
            assertFalse("Key " + me + " should not exist", r.containsKey(me));
          }
        }
        return null;
      }
Create a list of integers consisting of the ranges defined by the provided argument e.g..
createRanges(1, 4, 10, 12) means create ranges 1 through 4 and 10 through 12 and should yield
the list: 1, 2, 3, 4, 10, 11, 12
geode-core/src/distributedTest/java/org/apache/geode/cache/management/MemoryThresholdsOffHeapDUnitTest.java