code: @Override
      public CertPathValidatorResult engineValidate(CertPath cp,
                                                    CertPathParameters params)
          throws CertPathValidatorException, InvalidAlgorithmParameterException
      {
          ValidatorParams valParams = PKIX.checkParams(cp, params);
          return validate(valParams);
      }
docs: Validates a certification path consisting exclusively of
  <code>X509Certificate</code>s using the PKIX validation algorithm,
  which uses the specified input parameter set.
  The input parameter set must be a <code>PKIXParameters</code> object.
  
  @param cp the X509 certification path
  @param params the input PKIX parameter set
  @return the result
  @throws CertPathValidatorException if cert path does not validate.
  @throws InvalidAlgorithmParameterException if the specified
  parameters are inappropriate for this CertPathValidator