code: public boolean hasPolicyDatastream() throws ServerException {
  
          if (m_hasPolicyDatastream == null) {
              m_hasPolicyDatastream = false;
              Datastream[] allDs = getReader().GetDatastreams(null, null);
              for (int i = 0; i < allDs.length; i++) {
                  if (allDs[i].DatastreamID.equals(POLICY_DATASTREAM)) {
                      m_hasPolicyDatastream = true;
                      // also have the datastream now
                      m_datastream = allDs[i];
                      break;
                  }
              }
          }
          return m_hasPolicyDatastream;
      }
docs: determines if this object contains a policy datastream
  @return boolean
  @throws ServerException