@Override
      public String toString() {
        return String.format("Disconnect listener for %s", RemoteGfManagerAgent.this);
      }
Creates a new {@link InternalDistributedSystem} connection for this agent. If one alread
exists, it is {@code disconnected} and a new one is created.
geode-core/src/main/java/org/apache/geode/internal/admin/remote/RemoteGfManagerAgent.java