code: public int process() throws Exception {
          int changed = 0;
          for (File child : files) {
              changed += (processFile(child) != null ? 1 : 0);
          }
          return changed;
      }
docs: Processes the file, recursing as necessary, generating the source code.
  <p>
  The number of altered files is returned.
  
  @return the number of changed files
  @throws Exception if an error occurs