private function getDecoder(string $format, array $context): DecoderInterface
    {
        if (isset($this->decoderByFormat[$format])
            && isset($this->decoders[$this->decoderByFormat[$format]])
        ) {
            return $this->decoders[$this->decoderByFormat[$format]];
        }

        foreach ($this->decoders as $i => $decoder) {
            if ($decoder->supportsDecoding($format, $context)) {
                $this->decoderByFormat[$format] = $i;

                return $decoder;
            }
        }

        throw new RuntimeException(sprintf('No decoder found for format "%s".', $format));
    }