code: func (api *API) GetBundle(tailTxHash Hash) (bundle.Bundle, error) {
  	if err := Validate(ValidateTransactionHashes(tailTxHash)); err != nil {
  		return nil, err
  	}
  	var err error
  	bndl := bundle.Bundle{}
  	bndl, err = api.TraverseBundle(tailTxHash, bndl)
  	if err != nil {
  		return nil, err
  	}
  	if err := bundle.ValidBundle(bndl); err != nil {
  		return nil, err
  	}
  	return bndl, err
  }
docs: // GetBundle fetches and validates the bundle given a tail transaction hash by calling TraverseBundle
  // and traversing through trunk transactions.