code: public Map<String, String> parameters() {
          Map<String, String> ret = new HashMap<String, String>();
  
          if (getTransaction() != null) {
              ret.put("transaction", getTransaction());
          }
  
          if (getStartTime() > 0) {
              ret.put("startTime", "" + getStartTime());
          }
  
          if (getEndTime() > 0) {
              ret.put("endTime", "" + getEndTime());
          }
  
          if (!getProperties().isEmpty()) {
              boolean first = true;
              StringBuilder buf = new StringBuilder();
  
              for (PropertyCriteria pc : getProperties()) {
                  if (first) {
                      first = false;
                  } else {
                      buf.append(',');
                  }
                  buf.append(pc.encoded());
              }
  
              ret.put("properties", buf.toString());
          }
  
          if (hostName != null) {
              ret.put("hostName", hostName);
          }
  
          // Only relevant for trace fragments
          if (!getCorrelationIds().isEmpty()) {
              boolean first = true;
              StringBuilder buf = new StringBuilder();
  
              for (CorrelationIdentifier cid : getCorrelationIds()) {
                  if (first) {
                      first = false;
                  } else {
                      buf.append(',');
                  }
                  buf.append(cid.getScope().name());
                  buf.append('|');
                  buf.append(cid.getValue());
              }
  
              ret.put("correlations", buf.toString());
          }
  
          if (uri != null) {
              ret.put("uri", uri);
          }
  
          if (operation != null) {
              ret.put("operation", operation);
          }
  
          if (log.isLoggable(Level.FINEST)) {
              log.finest("Criteria parameters [" + ret + "]");
          }
  
          return ret;
      }
docs: This method returns the criteria as a map of name/value pairs.
  The properties and correlation ids are returned as a single
  entry with | separators.
  
  @return The criteria parameters