code: def _find_path(self, search_dirs, file_name):
          
          for dir_path in search_dirs:
              file_path = os.path.join(dir_path, file_name)
              if os.path.exists(file_path):
                  return file_path
  
          return None
docs: Search for the given file, and return the path.
  
          Returns None if the file is not found.