code: @Override
      public void start(BundleContext ctxt)
      {
          InputFactoryProviderImpl inputP = new InputFactoryProviderImpl();
          ctxt.registerService(Stax2InputFactoryProvider.class.getName(), inputP, inputP.getProperties());
          OutputFactoryProviderImpl outputP = new OutputFactoryProviderImpl();
          ctxt.registerService(Stax2OutputFactoryProvider.class.getName(), outputP, outputP.getProperties());
          ValidationSchemaFactoryProviderImpl[] impls = ValidationSchemaFactoryProviderImpl.createAll();
          for (int i = 0, len = impls.length; i < len; ++i) {
              ValidationSchemaFactoryProviderImpl impl = impls[i];
              ctxt.registerService(Stax2ValidationSchemaFactoryProvider.class.getName(), impl, impl.getProperties());
          }
      }
docs: Method called on activation. We need to register all providers we have at
  this point.