input: def parse_xml(text: str) -> List[Tag]:
      """ Parse an XML document and return a list of tag objects.
      Each Tag object contains an id and a list of values from the subchild elements.
  
      >>> xml_text = '''
      ... <xml>
      ...   <root>
      ...     <child1 id="1">
      ...       <subchild1 value="a"></subchild1>
      ...       <subchild2 value="b"></subchild2>
      ...     </child1>
      ...     <child2 id="2">
      ...       <subchild3 value="c"></subchild3>
      ...       <subchild4 value="d"></subchild4>
      ...     </child2>
      ...   </root>
      ... </xml>
      ... '''
      >>> parse_xml(xml_text)
      [Tag(tag_id='1', values=['a', 'b']), Tag(tag_id='2', values=['c', 'd'])]
      """
      tag_objects = []
  
      root = ET.fromstring(text)
      for child in root:
          tag = Tag(child.attrib["id"])
          for subchild in child:
              tag.add_value(subchild.attrib["value"])
          tag_objects.append(tag)
  
      return tag_objects
  
  class Tag:
      def __init__(self, tag_id):
          self.tag_id = tag_id
          self.values = []
      
      def add_value(self, value):
          self.values.append(value)
  
      def __repr__(self):
          return f"Tag(tag_id='{self.tag_id}', values={self.values})"
output:     import xml.etree.ElementTree as ET