DependencyInjection/Neo4jExtension.php
private function validateEntityManagers(array &$config): bool
    {
        $dependenciesInstalled = class_exists(EntityManager::class);
        $entityManagersConfigured = !empty($config['entity_managers']);

        if ($dependenciesInstalled && !$entityManagersConfigured) {
            // Add default entity manager if none set.
            $config['entity_managers']['default'] = ['client' => 'default'];
        } elseif (!$dependenciesInstalled && $entityManagersConfigured) {
            throw new \LogicException(
                'You need to install "graphaware/neo4j-php-ogm" to be able to use the EntityManager'
            );
        }

        return $dependenciesInstalled;
    }
private function validateEntityManagers(array &$config): bool
    {
        $dependenciesInstalled = class_exists(EntityManager::class);
        $entityManagersConfigured = !empty($config['entity_managers']);

        if ($dependenciesInstalled && !$entityManagersConfigured) {
            // Add default entity manager if none set.
            $config['entity_managers']['default'] = ['client' => 'default'];
        } elseif (!$dependenciesInstalled && $entityManagersConfigured) {
            throw new \LogicException(
                'You need to install "graphaware/neo4j-php-ogm" to be able to use the EntityManager'
            );
        }

        return $dependenciesInstalled;
    }
Make sure the EntityManager is installed if we have configured it.

@param array &$config

@return bool true if "graphaware/neo4j-php-ogm" is installed

@thorws \LogicException if EntityManagers os not installed but they are configured.