code: func newTxValidator(utxoView *UtxoViewpoint, flags txscript.ScriptFlags,
  	sigCache *txscript.SigCache, hashCache *txscript.HashCache) *txValidator {
  	return &txValidator{
  		validateChan: make(chan *txValidateItem),
  		quitChan:     make(chan struct{}),
  		resultChan:   make(chan error),
  		utxoView:     utxoView,
  		sigCache:     sigCache,
  		hashCache:    hashCache,
  		flags:        flags,
  	}
  }
docs: // newTxValidator returns a new instance of txValidator to be used for
  // validating transaction scripts asynchronously.