protected static function prePartial(&$context, $tmpl, &$name) {
        return $context['prepartial'] ? $context['prepartial']($context, $tmpl, $name) : $tmpl;
    }
protected static function prePartial(&$context, $tmpl, &$name) {
        return $context['prepartial'] ? $context['prepartial']($context, $tmpl, $name) : $tmpl;
    }
protected static function prePartial ( & $ context , $ tmpl , & $ name ) { return $ context [ 'prepartial' ] ? $ context [ 'prepartial' ] ( $ context , $ tmpl , $ name ) : $ tmpl ; }
preprocess partial template before it be stored into context

@param array<string,array|string|integer> $context Current context of compiler progress.
@param string $tmpl partial template
@param string $name partial name

@return string|null $content processed partial template

@expect 'hey' when input Array('prepartial' => false), 'hey', 'haha'
@expect 'haha-hoho' when input Array('prepartial' => function ($cx, $tmpl, $name) {return "$name-$tmpl";}), 'hoho', 'haha'
preprocess partial template before it be stored into context