DI\Definition\ObjectDefinition::classExists PHP Method

    public function classExists()
    {
        return $this->classExists;
    }

 private function assertClassExists(ObjectDefinition $definition)
 {
     if (!$definition->classExists()) {
         throw DefinitionException::create($definition, sprintf('Entry "%s" cannot be resolved: the class doesn\'t exist', $definition->getName()));
     }
 }