C++ Base Class Not Recognized

Greetings,
I have this c++ code:


namespace ModelAPI
{
	class ModelSignalBase
	{
	public:
		ModelSignalBase() 
		{ 
....

	class ModelSignal : public ModelSignalBase
	{
	public:
		/// <summary>
		/// Copy constructor.
		/// </summary>
		/// <param name="ms">ModelSignal to copy.</param>
		ModelSignal(const ModelSignal& ms)
....


In the generated cxx file the namespace is not included:

...
SWIGEXPORT void JNICALL Java_TiwsModelApiJNI_modelSignals_1set(JNIEnv *jenv, jclass jcls, jlong jarg1) {
  std::vector< ModelSignalBase * > arg1 ;
  std::vector< ModelSignalBase * > *argp1 ;
  
  (void)jenv;
  (void)jcls;
  argp1 = *(std::vector< ModelSignalBase * > **)&jarg1; 
  if (!argp1) {
...

The entire class structure that I'm wrapping in SWIG is in namespace ModelAPI. The code compiles and runs in C++.

Any hints or ideas appreciated.

Best regards,
Bill