mergeMap(msg => {
      const c = msg.content;
      const l = c.language_info;

      const info: KernelInfo = {
        protocolVersion: c.protocol_version,
        implementation: c.implementation,
        implementationVersion: c.implementation_version,
        banner: c.banner,
        helpLinks: c.help_links,
        languageName: l.name,
        languageVersion: l.version,
        mimetype: l.mimetype,
        fileExtension: l.file_extension,
        pygmentsLexer: l.pygments_lexer,
        codemirrorMode: l.codemirror_mode,
        nbconvertExporter: l.nbconvert_exporter
      };

      let result;
      if (!c.protocol_version.startsWith("5")) {
        result = [
          actions.launchKernelFailed({
            kernelRef,
            contentRef,
            error: new Error(
              "The kernel that you are attempting to launch does not support the latest version (v5) of the messaging protocol."
            )
          })
        ];
      } else {
        result = [
          // The original action we were using
          actions.setLanguageInfo({
            langInfo: msg.content.language_info,
            kernelRef,
            contentRef
          }),
          actions.setKernelInfo({
            kernelRef,
            info
          })
        ];
      }

      return of(...result);
    })

 catchError(error => {
   return of(actions.launchKernelFailed({ error }));
 })