/**
  * {@inheritdoc}
  */
 public function hasPluginClasses(Expression $expr = null)
 {
     if (!$expr) {
         return $this->rootPackageFile->hasPluginClasses();
     }
     foreach ($this->rootPackageFile->getPluginClasses() as $pluginClass) {
         if ($expr->evaluate($pluginClass)) {
             return true;
         }
     }
     return false;
 }
 public function testHasPluginClasses()
 {
     $this->assertFalse($this->packageFile->hasPluginClasses());
     $this->packageFile->addPluginClass(self::PLUGIN_CLASS);
     $this->assertTrue($this->packageFile->hasPluginClasses());
 }