code: protected long getAsyncShutdownTimeout(Dsn dsn) {
          return Util.parseLong(Lookup.lookup(ASYNC_SHUTDOWN_TIMEOUT_OPTION, dsn), ASYNC_SHUTDOWN_TIMEOUT_DEFAULT);
      }
docs: The graceful shutdown timeout of the async executor, in milliseconds.
  
  @param dsn Sentry server DSN which may contain options.
  @return The graceful shutdown timeout of the async executor, in milliseconds.