public function testAssemble()
 {
     $predicate = new NotBetweenPredicate();
     $predicate->setField('field');
     $this->assertEquals('field NOT BETWEEN NULL AND NULL', QueryAssembler::stringify($predicate));
     $predicate->setValues((new NumericExpression())->setValue(1), (new NumericExpression())->setValue(5));
     $this->assertEquals('field NOT BETWEEN 1 AND 5', QueryAssembler::stringify($predicate));
     $predicate->setValues((new NumericExpression())->setValue('1'), (new NumericExpression())->setValue('5'));
     $this->assertEquals('field NOT BETWEEN 1 AND 5', QueryAssembler::stringify($predicate));
     $predicate->setValues((new StringExpression())->setValue('abc'), (new StringExpression())->setValue('def'));
     $this->assertEquals('field NOT BETWEEN "abc" AND "def"', QueryAssembler::stringify($predicate));
     $predicate = NotBetweenPredicate::create('field', 123, 456);
     $this->assertEquals('field NOT BETWEEN 123 AND 456', QueryAssembler::stringify($predicate));
     $predicate = NotBetweenPredicate::create('field', 'abc', 'def');
     $this->assertEquals('field NOT BETWEEN "abc" AND "def"', QueryAssembler::stringify($predicate));
 }