code: private <Q extends IBaseExtension<?, ?>> List<IBaseExtension<?, ?>> toBaseExtensionList(final List<Q> theList) {
  		List<IBaseExtension<?, ?>> retVal = new ArrayList<IBaseExtension<?, ?>>(theList.size());
  		retVal.addAll(theList);
  		return retVal;
  	}
docs: This is just to work around the fact that casting java.util.List<ca.uhn.fhir.model.api.ExtensionDt> to
  java.util.List<? extends org.hl7.fhir.instance.model.api.IBaseExtension<?, ?>> seems to be
  rejected by the compiler some of the time.