@Override
  public boolean isActiveMaster() {
    return activeMaster;
  }
Report whether this master is currently the active master or not. If not active master, we are
parked on ZK waiting to become active. This method is used for testing.
@return true if active master, false if not.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java