Testing and documenting secure and unsecure ZK client connection from the same JVM

We are working in the ZooKeeper SSL integration in HBase. By default, one can enable ZooKeeper SSL client connections using Java System Properties. However, there are certain use-cases, when we need to connect to two ZooKeeper quorum from the same JVM (e.g. when connecting to two HBase clusters for data synchronization). It is possible, that one of the ZooKeeper quorum use SSL while the other doesn't.

In this case it is not possible to use Java System Properties, as those will be affecting both ZooKeeper client connections. These use-cases require code modifications e.g. in HBase to use custom ZooKeeper client configurations. We need to add unit test in ZooKeeper to verify that it works and also make sense to document this use-case to help other open source projects to start using ZooKeeper SSL.