code: def find(name, where):
      
      for cls in where:
          try:
              return {'ref': get(name, cls.__name__), 'name': name, 'cls': cls}
          except ChildNotFound:
              pass
      raise ChildNotFound(name)
docs: >>> from hl7apy.core import Segment
      >>> from hl7apy import find_reference
      >>> find_reference('UNKNOWN', (Segment, ), '2.3.1')  # doctest: +IGNORE_EXCEPTION_DETAIL
      Traceback (most recent call last):
      ...
      ChildNotFound: No child named UNKNOWN