### Question:
LessOperator extends AbstractOperator implements RelationalOperator { @Override public Predicate toPredicate(String prop, String val) { return new LessPredicate<>(prop, val); } LessOperator(); @Override TYPE getType(); @Override Predicate toPredicate(String prop, String val); @Override String getName();  }### Answer:
@Test public void testToPredicate() { assertEquals(new LessPredicate<>("1", "2"), new LessOperator().toPredicate("1", "2")); }