code: String partialEncode() {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "partialEncode()");
  
          String encoded = null;
  
          // If we have a cached version of the string, use it.
          if (cachedPartialEncodedString != null) {
              encoded = cachedPartialEncodedString;
          }
  
          else {
              // Get a copy of the properties which make up this Destination. We need a
              // copy since we remove the jms name before iterating over the other
              // properties, and encoding them.
              Map<String, Object> destProps = getCopyOfProperties();
  
              // Remove the props that are stored in the reply header.
              // NB. The deliveryMode is used in the  creation of the reply header,
              //      but must still be carried.
              destProps.remove(JmsInternalConstants.DEST_NAME);
              destProps.remove(JmsInternalConstants.DEST_DISCRIM);
              destProps.remove(JmsInternalConstants.PRIORITY);
              destProps.remove(JmsInternalConstants.TIME_TO_LIVE);
  
              destProps.remove(JmsInternalConstants.FORWARD_ROUTING_PATH);
              destProps.remove(JmsInternalConstants.REVERSE_ROUTING_PATH);
  
              // Pass off to a common helper method (between full and partial encodings).
              encoded = encodeMap(destProps);
  
              // Now store this string in the cache in case we need it later.
              cachedPartialEncodedString = encoded;
          }
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "partialEncode", encoded);
          return encoded;
      }
docs: A variant of the fullEncode method that is used for URI-encoding for the
  purposes of setting it into the jmsReplyTo field of the core message.
  
  This is different from full encode because some of the fields of the destination
  are stored in the message reply header so that they can be accessed and
  altered by core SPI applications / mediations.
  
  TODO: This is only used by Unit tests, and those tests appear to be simply
  testing this method - so scrap it & them?