code: def acquire(self, **kwargs):
          
          path = path_string(self.path)
          if os.path.exists(path):
              if config.verify_file(path, self.sha256):
                  return path
          return None
docs: Copy the file and return its path
  
          Returns
          -------
          str or None
              The path of the file or None if it does not exist or if
              verification failed.