public function testUnsetChild()
{
$this->_populateSampleStructure();
// specify element by name
$this->_structure->unsetChild('five');
$this->assertFalse($this->_structure->getParentId('five'));
$this->assertArrayNotHasKey(Magento_Data_Structure::CHILDREN, $this->_structure->getElement('six'));
// specify element by parent and alias
$this->_structure->unsetChild('four', 'tw');
$this->assertFalse($this->_structure->getChildId('four', 'tw'));
$this->assertFalse($this->_structure->getParentId('two'));
}