### Question:
QLIT extends QNODE<LIT> { public Predicate isEmpty() { return BooleanOperation.create(Ops.STRING_IS_EMPTY, this); } QLIT(String variable); BooleanExpression lt(String val); BooleanExpression gt(String val); BooleanExpression loe(String val); BooleanExpression goe(String val); BooleanExpression lt(LIT val); BooleanExpression gt(LIT val); BooleanExpression loe(LIT val); BooleanExpression goe(LIT val); BooleanExpression like(String val); BooleanExpression matches(String val); Predicate isEmpty(); Predicate eqIgnoreCase(String val);  }### Answer:
@Test public void IsEmpty() { assertEquals("empty({lit})", lit.isEmpty().toString()); }