protected function validatePrototypeNode(PrototypedArrayNode $node)
    {
        $path = $node->getPath();

        if ($this->addDefaults) {
            throw new InvalidDefinitionException(
                sprintf('->addDefaultsIfNotSet() is not applicable to prototype nodes at path "%s"', $path)
            );
        }

        if (false !== $this->addDefaultChildren) {
            if ($this->default) {
                throw new InvalidDefinitionException(
                    sprintf('A default value and default children might not be used together at path "%s"', $path)
                );
            }

            if (null !== $this->key && (null === $this->addDefaultChildren || is_int($this->addDefaultChildren) && $this->addDefaultChildren > 0)) {
                throw new InvalidDefinitionException(
                    sprintf('->addDefaultChildrenIfNoneSet() should set default children names as ->useAttributeAsKey() is used at path "%s"', $path)
                );
            }

            if (null === $this->key && (is_string($this->addDefaultChildren) || is_array($this->addDefaultChildren))) {
                throw new InvalidDefinitionException(
                    sprintf('->addDefaultChildrenIfNoneSet() might not set default children names as ->useAttributeAsKey() is not used at path "%s"', $path)
                );
            }
        }
    }