input: 
  def parse_xml(text):
      """
      Parse an XML document and return a list of tag objects, each containing an ID and associated values.
      
      >>> xml_input = '''<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>'''
      >>> result = parse_xml(xml_input)
      >>> for tag in result:
      ...     print(f"ID: {tag.tag_id}, Values: {tag.values}")
      ID: 1, Values: ['a', 'b']
      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)
  
output:     import xml.etree.ElementTree as ET