ifNull example

$test = $this->getTestBuilder()
            ->ifString()
            ->then($this->returnClosure('new_value'))
        ->end();
        $this->assertFinalizedValueIs(45, $test, ['key' => 45]);
    }

    public function testIfNullExpression()
    {
        $test = $this->getTestBuilder()
            ->ifNull()
            ->then($this->returnClosure('new_value'))
        ->end();
        $this->assertFinalizedValueIs('new_value', $test, ['key' => null]);

        $test = $this->getTestBuilder()
            ->ifNull()
            ->then($this->returnClosure('new_value'))
        ->end();
        $this->assertFinalizedValueIs('value', $test);
    }