public static CommonCertificateVerifier getVerifier(boolean isIndividual) {
        if (isIndividual) {
            if (individualVerifier == null) {
                individualVerifier = loadClass(System.getProperty("INDIVIDUAL_CERT_VERIFIER_CLASS_NAME"));
            }
            return individualVerifier;
        } else {
            if (corporateVerifier == null) {
                corporateVerifier = loadClass(System.getProperty("CORPORATE_CERT_VERIFIER_CLASS_NAME"));
            }
            return corporateVerifier;
        }
    }
@Test
    public void testGetVerifierIsInstanceOfNullJuridicalCertificateVerifierOnInvalidEnvironment() throws Exception {
        Field singleton = CertificateVerifierHolder.class.getDeclaredField("individualVerifier");
        singleton.setAccessible(true);
        singleton.set(null, null);
        CommonCertificateVerifier verifier = CertificateVerifierHolder.getVerifier(true);
        assertThat(verifier).isInstanceOf(NullCommonCertificateVerifier.class);
    }