private void createDirectoryIfNotYetExists(final File directory) {
   diffFiles.assertRootDirectoryExists();
   if (!directory.exists()) {
     directory.mkdirs();
   }
 }
 private void createComparisonDirectoryIfNotYetExists() {
   createDirectoryIfNotYetExists(
       diffFiles.getComparisonDirectory(baseBranchName, baseBuildName, comparisonName));
 }