@Test
    public void testMissingPrivateKey() {
        val config = new ECSignatureConfiguration();
        TestsHelper.expectException(() -> config.sign(buildClaims()), TechnicalException.class, "privateKey cannot be null");
    }
Tests {@link ECSignatureConfiguration}.

@author Jerome Leleu
@since 1.9.2
pac4j-jwt/src/test/java/org/pac4j/jwt/config/signature/ECSignatureConfigurationTests.java