docs: protected HashMap<String, byte[]> doBuildZipPass(final BuildData buildData) throws BuildProcessingException {
          log.info("Building the ZIP file");
  
          // Add the base book information
          final HashMap<String, byte[]> files = buildData.getOutputFiles();
  
          // Add the additional files
          buildBookAdditions(buildData);
  
          // add the images to the book
          addImagesToBook(buildData);
  
          // add any additional files to the book
          addAdditionalFilesToBook(buildData);
  
          // Build the book base
          buildBookBase(buildData);
  
          return files;
      }