code: def child_cardinality(self, child):
          
          for prop, klassdef in self.c_children.values():
              if child == prop:
                  if isinstance(klassdef, list):
                      try:
                          _min = self.c_cardinality["min"]
                      except KeyError:
                          _min = 1
                      try:
                          _max = self.c_cardinality["max"]
                      except KeyError:
                          _max = "unbounded"
  
                      return _min, _max
                  else:
                      return 1, 1
          return None
docs: Return the cardinality of a child element
  
          :param child: The name of the child element
          :return: The cardinality as a 2-tuple (min, max).
              The max value is either a number or the string "unbounded".
              The min value is always a number.