public function testAliasedProperties()
 {
     $this->mapping->setPropertyNameAliases(['oldName' => 'newName']);
     $this->assertEquals(['oldName' => 'newName'], $this->mapping->getAliasedProperties());
     $this->mapping->addPropertyAlias('oldName2', 'newName2');
     $this->assertEquals(['oldName' => 'newName', 'oldName2' => 'newName2'], $this->mapping->getAliasedProperties());
 }