public Integer waitForId() {
      try {
        waitForRepliesUninterruptibly();
      } catch (ReplyException e) {
        logger.debug("{} waitBucketSizes ignoring exception {}", getClass().getName(),
            e.getMessage(), e);
      }
      synchronized (this) {
        return returnValue;
      }
    }
Fetch the next <code>PartitionedRegion</code> identity, used to uniquely identify (globally)
each instance of a <code>PartitionedRegion</code>

@return the next highest Integer for the <code>PartitionedRegion</code> or null if this is
        the first identity

@see PartitionMessage#getRegionId()
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/IdentityRequestMessage.java