code: public ServiceReference<?>[] fetchReferences() {
          try {
              LOGGER.debug("Try to locate a suitable service for objectClass = "
                      + serviceInterface + " and filter = " + filterString);
              return bundleContext.getAllServiceReferences(serviceInterface, filterString);
          } catch (InvalidSyntaxException e) {
              LOGGER.error("Creation of filter failed: {}", e.getMessage(), e);
              throw new RuntimeException("Creation of filter failed", e);
          }
      }
docs: <p>fetchReferences.</p>
  
  @return an array of {@link org.osgi.framework.ServiceReference} objects.