code: public static WsLocationAdminImpl createLocations(final BundleContext ctx) {
          if (instance.get() == null) {
              SymbolRegistry.getRegistry().clear();
              Callable<WsLocationAdminImpl> initializer = new Callable<WsLocationAdminImpl>() {
                  @Override
                  public WsLocationAdminImpl call() throws Exception {
                      return new WsLocationAdminImpl(new BundleContextMap(ctx));
                  }
              };
              instance = StaticValue.mutateStaticValue(instance,initializer);
          }
  
          return instance.get();
      }
docs: Construct the WsLocationAdminService singleton based on a set of initial
  properties provided by the bundle context when running in an osgi
  framework.
  
  @param initProps
  @return WsLocationAdmin