docs: def snap(self, path=None):
          """Get a snapshot and save it to disk."""
          if path is None:
              path = "/tmp"
          else:
              path = path.rstrip("/")
          day_dir = datetime.datetime.now().strftime("%d%m%Y")
          hour_dir = datetime.datetime.now().strftime("%H%M")
          ensure_snapshot_dir(path+"/"+self.cam_id+"/"+day_dir+"/"+hour_dir)
          f_path = "{0}/{1}/{2}/{3}/{4}.jpg".format(
                  path,
                  self.cam_id,
                  day_dir,
                  hour_dir,
                  datetime.datetime.now().strftime("%S"),
          )
  
          urllib.urlretrieve(
              'http://{0}/snapshot.cgi?user={1}&pwd={2}'.format(
                                      self.address, 
                                      self.user, 
                                      self.pswd,
                                      ),
              f_path,
          )