code: public static ComapiClient createShared(@NonNull ComapiConfig config) {
  
          if (instance == null) {
              synchronized (ComapiClient.class) {
                  if (instance == null) {
                      instance = new ComapiClient(config);
                  }
              }
          }
  
          return instance;
      }
docs: Get global singleton of {@link ComapiClient}.
  
  @return Singleton of {@link ComapiClient}