public function testEnforceVersioning()
 {
     $bar = new \VersionableBehaviorTest10();
     $bar->setBar(42);
     $bar->save();
     $this->assertEquals(1, $bar->getVersion());
     $this->assertFalse($bar->isVersioningNecessary());
     $bar->enforceVersioning();
     $this->assertTrue($bar->isVersioningNecessary());
     $bar->save();
     $this->assertEquals(2, $bar->getVersion());
 }