@Test
    void spliteratorCharacteristics() {
        final int c = instance.spliterator().characteristics();
        assertHasFlag(c, Spliterator.DISTINCT);
        assertHasFlag(c, Spliterator.IMMUTABLE);
        assertHasFlag(c, Spliterator.ORDERED);
        assertHasFlag(c, Spliterator.SIZED);
        assertHasFlag(c, Spliterator.SUBSIZED);
        assertHasFlag(c, Spliterator.NONNULL);
    }
Test of mapToInt method, of class SingletonStream.
common-parent/singletonstream/src/test/java/com/speedment/common/singletonstream/SingletonStreamTest.java