public function testInvalidClassNames()
 {
     $this->assertFalse(\Phruts\Util\ClassLoader::isValidClassName('\\1Doctrine\\Common\\IsolatedClassLoader'), '\\1Doctrine\\Common\\IsolatedClassLoader');
     $this->assertFalse(\Phruts\Util\ClassLoader::isValidClassName('Doctrine\\Common\\IsolatedClassLoader'), 'Doctrine\\Common\\IsolatedClassLoader');
     $this->assertFalse(\Phruts\Util\ClassLoader::isValidClassName('\\Doctrine\\Common\\Isolated.ClassLoader'), 'Doctrine\\Common\\Isolated.ClassLoader');
     $this->assertFalse(\Phruts\Util\ClassLoader::isValidClassName(''));
 }