src/Routelocale.php
public function getRouteLocalePrefix($locale = null) {
        if (is_null($locale)) {
            $locale = $this->getLocaleFromRoute();
        }
        return $this->getDefaultRoutelocale() === $locale ? ($this->isUsePrefixForDefaultLocale() ? $locale : '') : $locale;
    }
public function getRouteLocalePrefix($locale = null) {
        if (is_null($locale)) {
            $locale = $this->getLocaleFromRoute();
        }
        return $this->getDefaultRoutelocale() === $locale ? ($this->isUsePrefixForDefaultLocale() ? $locale : '') : $locale;
    }
public function getRouteLocalePrefix ( $ locale = null ) { if ( is_null ( $ locale ) ) { $ locale = $ this -> getLocaleFromRoute ( ) ; } return $ this -> getDefaultRoutelocale ( ) === $ locale ? ( $ this -> isUsePrefixForDefaultLocale ( ) ? $ locale : '' ) : $ locale ; }
Returns locale to set as prefix to the route.
Returns empty string it is default locale and if configuration set to "no prefix" for default locale

@param type $locale
@return string Prefix to localized route. Like 'en'.
Returns locale to set as prefix to the route . Returns empty string it is default locale and if configuration set to no prefix for default locale