code: func (api *API) BroadcastBundle(tailTxHash Hash) ([]Trytes, error) {
  	if err := Validate(ValidateTransactionHashes(tailTxHash)); err != nil {
  		return nil, err
  	}
  
  	bndl, err := api.GetBundle(tailTxHash)
  	if err != nil {
  		return nil, err
  	}
  	trytes := transaction.MustFinalTransactionTrytes(bndl)
  	return api.BroadcastTransactions(trytes...)
  }
docs: // BroadcastBundle re-broadcasts all transactions in a bundle given the tail transaction hash.
  // It might be useful when transactions did not properly propagate, particularly in the case of large bundles.