code: public CompletableFuture<NamespaceInfo> getNamespaceInfoAsync() {
          CompletableFuture<String> contentFuture = getEntityAsync("$namespaceinfo", null, false);
          CompletableFuture<NamespaceInfo> nsInfoFuture = new CompletableFuture<>();
          contentFuture.handleAsync((content, ex) -> {
              if (ex != null) {
                  nsInfoFuture.completeExceptionally(ex);
              } else {
                  try {
                      nsInfoFuture.complete(NamespaceInfoSerializer.parseFromContent(content));
                  } catch (ServiceBusException e) {
                      nsInfoFuture.completeExceptionally(e);
                  }
              }
              return null;
          }, MessagingFactory.INTERNAL_THREAD_POOL);
  
          return nsInfoFuture;
      }
docs: Retrieves information related to the namespace.
  Works with any claim (Send/Listen/Manage).
  @return - {@link NamespaceInfo} containing namespace information.