@Test
    void takeWhile() {
        assertEquals(1, instance.takeWhile(ELEMENT::equals).count());
        assertEquals(0, instance.takeWhile(OTHER_ELEMENT::equals).count());
    }
Test of mapToInt method, of class SingletonStream.
common-parent/singletonstream/src/test/java/com/speedment/common/singletonstream/SingletonStreamTest.java