@Test
    @SuppressWarnings("PMD.JUnitTestsShouldIncludeAssert") // is done in called test method
    public void rangeFromValues() {
        assertSingle(c -> c.setDifficulty(5f), f -> f.setRangeFromValues(Arrays.asList(2f, 5f)), true);
        assertSingle(c -> c.setDifficulty(5f), f -> f.setRangeFromValues(Arrays.asList(2f, 3f)), false);
        assertSingle(c -> c.setDifficulty(5f), f -> f.setRangeFromValues(Arrays.asList(2f, 3f), 2f, 3f), true);
        assertSingle(c -> c.setDifficulty(1f), f -> f.setRangeFromValues(Arrays.asList(2f, 3f), 2f, 3f), true);
    }
This class tests the number range filters, using DIFFICULTY filter as an example
main/src/androidTest/java/cgeo/geocaching/filters/NumberRangeGeocacheFilterTest.java