code: private boolean isReady() {
      if (this.status != Status.READY) {
        // e.g. if the node is disabled, it is not ready to run.
        return false;
      }
      for (final Node parent : this.parents) {
        if (!parent.status.isSuccessEffectively()) {
          return false;
        }
      }
      return true;
    }
docs: Checks if the node is ready to run.
  
  @return true if the node is ready to run