input: 
  def parse_xml(text: str) -> List[Tag]:
      """ Parse an XML document and return a list of Tag objects, each representing a child tag with its attributes and subchildren's values.
      >>> example_xml = '''<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>'''
      >>> parsed_tags = parse_xml(example_xml)
      >>> [tag.tag_id for tag in parsed_tags]
      ['1', '2']
      >>> [tag.values for tag in parsed_tags]
      [['a', 'b'], ['c', 'd']]
      """
      import xml.etree.ElementTree as ET
  
      class Tag:
          def __init__(self, tag_id):
              self.tag_id = tag_id
              self.values = []
          
          def add_value(self, value):
              self.values.append(value)
  
      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
  
output:     
      import xml.etree.ElementTree as ET
  
      class Tag:
          def __init__(self, tag_id):
              self.tag_id = tag_id
              self.values = []
          
          def add_value(self, value):
              self.values.append(value)
  
      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
  