src/Phug/Partial/ExtensionsTrait.php
public static function getExtensionsOptions(array $extensions, array $options = [])
    {
        $methods = static::getExtensionsGetters();
        foreach ($extensions as $extensionClassName) {
            if (is_a($extensionClassName, ModuleInterface::class, true)) {
                if (!isset($options['modules'])) {
                    $options['modules'] = [];
                }
                $options['modules'][] = $extensionClassName;

                continue;
            }

            static::extractExtensionOptions($options, $extensionClassName, $methods);
        }

        return $options;
    }
public static function getExtensionsOptions(array $extensions, array $options = [])
    {
        $methods = static::getExtensionsGetters();
        foreach ($extensions as $extensionClassName) {
            if (is_a($extensionClassName, ModuleInterface::class, true)) {
                if (!isset($options['modules'])) {
                    $options['modules'] = [];
                }
                $options['modules'][] = $extensionClassName;

                continue;
            }

            static::extractExtensionOptions($options, $extensionClassName, $methods);
        }

        return $options;
    }
Get options from extensions list and default options.

@param array $extensions list of extensions instances of class names
@param array $options    optional default options to merge with

@return array