code: def add(self, *items):
      for item in items:
          if not self._values.get(item, False):
              self._values.update({item: True})
              self.items.append(item)
  
file_path: pyecharts/pyecharts/commons/utils.py
imports: import re
  from ..datasets import EXTRA, FILENAMES
label_desc: Use image node_id 2 for calling the OrderedSet obj's underlying member method code with example usage: obj.add() without return types