@Test
    @SuppressWarnings("PMD.JUnitTestsShouldIncludeAssert") // is done in called test method
    public void simple() {
        assertSingle(c -> c.setDifficulty(2f), f -> f.setMinMaxRange(2f, 2f), true);
        assertSingle(c -> c.setDifficulty(2f), f -> f.setMinMaxRange(1.5f, 3f), true);
        assertSingle(c -> c.setDifficulty(2f), f -> f.setMinMaxRange(2.5f, 4f), false);
    }
This class tests the number range filters, using DIFFICULTY filter as an example
main/src/androidTest/java/cgeo/geocaching/filters/NumberRangeGeocacheFilterTest.java