@Test
public void isAlphaNumericTest() {

    try {
        Method method = ElkConnectorImpl.class.getDeclaredMethod("isAlphaNumeric", String.class);
        method.setAccessible(true);
        assertTrue((boolean) method.invoke(new ElkConnectorImpl(), "abc123"));
        assertFalse((boolean) method.invoke(new ElkConnectorImpl(), "abc123*"));
        assertFalse((boolean) method.invoke(new ElkConnectorImpl(), "abc123{}"));
        assertFalse((boolean) method.invoke(new ElkConnectorImpl(), "abc123\n"));
        assertFalse((boolean) method.invoke(new ElkConnectorImpl(), "abc123<"));
        assertFalse((boolean) method.invoke(new ElkConnectorImpl(), "abc123:"));
    } catch (Exception e) {
        fail();
    }
}