src/Provider/Silex/VarsServiceProvider.php
private function createKeyedOptions($options, $vars_options)
    {
        foreach ($this->option_keys as $option) {
            $options[$option] = (isset($vars_options[$option])) ? $vars_options[$option] : null;
        }

        return $options;
    }
private function createKeyedOptions($options, $vars_options)
    {
        foreach ($this->option_keys as $option) {
            $options[$option] = (isset($vars_options[$option])) ? $vars_options[$option] : null;
        }

        return $options;
    }
Registers the service provider, sets the user defined options and returns the vars instance

@param array $options      The already parsed options
@param array $vars_options The options defined in the Silex app

@return array The keyed options