code: public void file(String filename, InputStream input) {
          checkCommitted();
  
          // content type to OCTET_STREAM if it's not set
          if (getContentType() == null) {
              contentType(mimeTypes.getContentType(filename, HttpConstants.ContentType.APPLICATION_OCTET_STREAM));
          }
  
          if (isHeaderEmpty(HttpConstants.Header.CONTENT_DISPOSITION)) {
              filenameHeader(filename);
          }
  
          finalizeResponse();
  
          try {
              send(input);
          } catch (IOException e) {
              throw new PippoRuntimeException(e);
          }
      }
docs: Copies the input stream to the response output stream as a download and closes the input stream upon completion.
  <p>This method commits the response.</p>
  
  @param filename
  @param input