public function testGetSetChildrenLabelFields()
{
$read = $this->definitionLibrary->getChildrenLabelFields();
$expected = ['book' => 'title'];
$this->assertSame($read, $expected);
$expected = ['book' => 'author'];
$this->definitionLibrary->setChildrenLabelFields($expected);
$read = $this->definitionLibrary->getChildrenLabelFields();
$this->assertSame($read, $expected);
}