private static void waitForEntry(final Region r, final Object key) {
    await().alias("Waiting for entry " + key + " on region " + r)
        .until(() -> r.containsValueForKey(key));
  }
A handy method to poll for arrival of non-null/non-invalid entries

@param r the Region to poll
@param key the key of the Entry to poll for
geode-core/src/distributedTest/java/org/apache/geode/cache/ConnectionPoolDUnitTest.java