@Test
    public void testTail() {
        assertMetrics("tail:0","a","a");
        assertMetrics("tail:0","y","a");
        assertMetrics("tail:1","a","a x");
        assertMetrics("tail:2","a b c","a b c x x");
        assertMetrics("tail:2","a b c","x x x c x x x x a b x x");
        assertMetrics("tail:0","a b c","x x c x x x x x x x x x x x x x x x a b");
    }
Tests of calculation of all the string match metrics.
Add true as the fourth parameter to assertMetrics to see a trace of what the test is doing.

@author bratseth
searchlib/src/test/java/com/yahoo/searchlib/ranking/features/fieldmatch/test/FieldMatchMetricsTestCase.java