src/CacheStorage.php
private function persistHeaders(MessageInterface $message)
    {
        // Clone the response to not destroy any necessary headers when caching
        $headers = array_diff_key($message->getHeaders(), self::$noCache);

        // Cast the headers to a string
        foreach ($headers as &$value) {
            $value = implode(', ', $value);
        }

        return $headers;
    }
private function persistHeaders(MessageInterface $message)
    {
        // Clone the response to not destroy any necessary headers when caching
        $headers = array_diff_key($message->getHeaders(), self::$noCache);

        // Cast the headers to a string
        foreach ($headers as &$value) {
            $value = implode(', ', $value);
        }

        return $headers;
    }
private function persistHeaders ( MessageInterface $ message ) { // Clone the response to not destroy any necessary headers when caching $ headers = array_diff_key ( $ message -> getHeaders ( ) , self :: $ noCache ) ; // Cast the headers to a string foreach ( $ headers as & $ value ) { $ value = implode ( ', ' , $ value ) ; } return $ headers ; }
Creates an array of cacheable and normalized message headers.

@param MessageInterface $message

@return array
Creates an array of cacheable and normalized message headers .