code: public Collection<Participant> getParticipants() throws Exception
      {
          Collection<String> participantNodes = mutex.getParticipantNodes();
  
          return getParticipants(client, participantNodes);
      }
docs: <p>
  Returns the set of current participants in the leader selection
  </p>
  <p>
  <p>
  <B>NOTE</B> - this method polls the ZK server. Therefore it can possibly
  return a value that does not match {@link #hasLeadership()} as hasLeadership
  uses a local field of the class.
  </p>
  
  @return participants
  @throws Exception ZK errors, interruptions, etc.