code: @Override
      public EndpointReferenceType getAddressWithId(String id) {
          EndpointReferenceType ref = null;
  
          if (isMultiplexWithAddress()) {
              String address = EndpointReferenceUtils.getAddress(reference);
              ref = EndpointReferenceUtils.duplicate(reference);
              if (address.endsWith("/")) {
                  EndpointReferenceUtils.setAddress(ref, address + id);
              } else {
                  EndpointReferenceUtils.setAddress(ref, address + "/" + id);
              }
          } else {
              ref = super.getAddressWithId(id);
          }
          return ref;
      }
docs: /*
  Implement multiplex via the address URL to avoid the need for ws-a.
  Requires contextMatchStrategy of stem.
  
  @see org.apache.cxf.transport.AbstractMultiplexDestination#getAddressWithId(java.lang.String)