How to use the pdfjs-dist.UnexpectedResponseException function in pdfjs-dist

}, function (exception) {
      let message = exception && exception.message
      let l10n = self.l10n
      let loadingErrorMessage

      if (exception instanceof pdfjsLib.InvalidPDFException) {
        // change error message also for other builds
        loadingErrorMessage = l10n.get('invalid_file_error', null,
          'Invalid or corrupted PDF file.')
      } else if (exception instanceof pdfjsLib.MissingPDFException) {
        // special message for missing PDFs
        loadingErrorMessage = l10n.get('missing_file_error', null,
          'Missing PDF file.')
      } else if (exception instanceof pdfjsLib.UnexpectedResponseException) {
        loadingErrorMessage = l10n.get('unexpected_response_error', null,
          'Unexpected server response.')
      } else {
        loadingErrorMessage = l10n.get('loading_error', null,
          'An error occurred while loading the PDF.')
      }

      loadingErrorMessage.then(function (msg) {
        //console.log(msg)
      })
      self.loadingBar.hide()
    })
  }

}, function (exception) {
      let message = exception && exception.message
      let l10n = self.l10n
      let loadingErrorMessage

      if (exception instanceof pdfjsLib.InvalidPDFException) {
        // change error message also for other builds
        loadingErrorMessage = l10n.get('invalid_file_error', null,
          'Invalid or corrupted PDF file.')
      } else if (exception instanceof pdfjsLib.MissingPDFException) {
        // special message for missing PDFs
        loadingErrorMessage = l10n.get('missing_file_error', null,
          'Missing PDF file.')
      } else if (exception instanceof pdfjsLib.UnexpectedResponseException) {
        loadingErrorMessage = l10n.get('unexpected_response_error', null,
          'Unexpected server response.')
      } else {
        loadingErrorMessage = l10n.get('loading_error', null,
          'An error occurred while loading the PDF.')
      }

      loadingErrorMessage.then(function (msg) {
      })
      self.loadingBar.hide()
    })
  }