code: 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;
      }
docs: Wrap all of the topics, images, common content, etc... files into a ZIP Archive.
  
  @param buildData Information and data structures for the build.
  @return A ZIP Archive containing all the information to build the book.
  @throws BuildProcessingException Any build issue that should not occur under normal circumstances. Ie a Template can't be
  converted to a DOM Document.