code: func NewChainAsyncResult(tasks []*tasks.Signature, backend iface.Backend) *ChainAsyncResult {
  	asyncResults := make([]*AsyncResult, len(tasks))
  	for i, task := range tasks {
  		asyncResults[i] = NewAsyncResult(task, backend)
  	}
  	return &ChainAsyncResult{
  		asyncResults: asyncResults,
  		backend:      backend,
  	}
  }
docs: // NewChainAsyncResult creates ChainAsyncResult instance