code: CompletableFuture<Integer> getNextStreamPosition() {
          return store.createEphemeralSequentialZNode(counterPath)
                      .thenApply(counterStr -> Integer.parseInt(counterStr.replace(counterPath, "")));
      }
docs: When a new stream is created under a scope, we first get a new counter value by creating a sequential znode under
  a counter node. this is a 10 digit integer which the store passes to the zkscope object as position.
  @return A future which when completed has the next stream position represented by an integer.