code: public ZipMessage addEntry(File file) {
          try {
              addEntry(new Entry(file));
          } catch (IOException e) {
              throw new CitrusRuntimeException("Failed to read zip entry content from given file", e);
          }
          return this;
      }
docs: Adds new zip archive entry. Entry can be a file or directory. In case of directory all files will be automatically added
  to the zip archive. Directory structures are retained throughout this process.
  @param file
  @return