docs: def assure_cache(project_path=None):
      """
      Assure that a project directory has a cache folder.
      If not, it will create it.
      """
  
      project_path = path(project_path, ISDIR)
      cache_path = os.path.join(project_path, CACHE_NAME)
  
      if not os.path.isdir(cache_path):
          os.mkdir(cache_path)