code: @Override
      @Trivial
      public ZipFile open() throws IOException {
          String methodName = "open";
  
          synchronized( zipFileLock ) {
              if ( zipFile == null ) {
                  debug(methodName, "Opening");
                  if ( zipFileReaper == null ) {
                      zipFile = ZipFileUtils.openZipFile(file); // throws IOException
                  } else {
                      zipFile = zipFileReaper.open(path);
                  }
              }
  
              openCount++;
              debug(methodName, "Opened");
  
              return zipFile;
          }
      }
docs: Open the zip file.  Create and assign the zip file if this is the first
  open.  Increase the open count by one.
  
  If this is the first open and the zip file could not be created, the
  open count is not increased.
  
  @return The zip file.