code: public static IAsyncProvider getInstance() {
          if (instance != null) {
              return instance;
          }
          try {
              return createInstance();
          } catch (AsyncException x) {
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
                  Tr.debug(tc, "Error getting async provider instance, exception: " + x.getMessage());
              }
              FFDCFilter.processException(x, "com.ibm.io.async.AsyncLibrary", "331");
              return null;
          }
      }
docs: Get the singleton instance of the async library.
  
  @return IasyncProvider