code: public X509CertChainValidatorExt build() {
  
      RevocationParametersExt revocationParameters = new RevocationParametersExt(
        crlChecks, new CRLParameters(), new OCSPParametes(ocspChecks));
  
      ValidatorParamsExt validationParams = new ValidatorParamsExt(
        revocationParameters, ProxySupport.ALLOW);
  
      if (storeUpdateListener != null){
        validationParams.setInitialListeners(Arrays.asList(storeUpdateListener));
      }
      
      boolean openssl1xMode = false;
      
      if (opensslHashFunction == OpensslHashFunction.SHA1){
        openssl1xMode = true;
      }
      
      OpensslCertChainValidator validator = new OpensslCertChainValidator(
        trustAnchorsDir, openssl1xMode, namespaceChecks, trustAnchorsUpdateInterval,
        validationParams, lazyAnchorsLoading);
  
      if (validationErrorListener != null){
        validator.addValidationListener(validationErrorListener);
      }
      
      return validator;
    }
docs: Builds an {@link OpensslCertChainValidator} according to the parameters set
  for this builder
  
  @return the {@link X509CertChainValidatorExt}