public static FingerprintTrustManagerFactoryBuilder builder(String algorithm) {
        return new FingerprintTrustManagerFactoryBuilder(algorithm);
    }
@Test
    public void testWithNullFingerprint() {
        assertThrows(IllegalArgumentException.class, new Executable() {
            @Override
            public void execute() {
                FingerprintTrustManagerFactory
                        .builder("SHA-256")
                        .fingerprints(FIRST_CERT_SHA256_FINGERPRINT, null)
                        .build();
            }
        });
    }