private function validateClass(Definition $definition)
{
$class = $definition->getClass();
if ($class) {
$class = $this->containerBuilder->getParameterBag()->resolveValue($class);
// TODO only services created using a factory can have an interface
if (!class_exists($class) && !interface_exists($class)) {
throw new ClassNotFoundException($class);
}
} elseif ($this->shouldDefinitionHaveAClass($definition)) {
throw new DefinitionHasNoClassException();
}
}