Neomerx\JsonApi\Contracts\Codec\CodecMatcherInterface::registerDecoder PHP Method

    public function registerDecoder(MediaTypeInterface $mediaType, Closure $decoderClosure);

 /**
  * @param string $mediaType
  * @return $this
  */
 private function withMediaType($mediaType = MediaTypeInterface::JSON_API_MEDIA_TYPE)
 {
     $mediaType = MediaType::parse(0, $mediaType);
     $this->codecMatcher->registerEncoder($mediaType, function () {
         return Encoder::instance();
     });
     $this->codecMatcher->registerDecoder($mediaType, function () {
         return new DocumentDecoder();
     });
     return $this;
 }