code: def _default_child_lookup(self, name):
          
          if name in self.indexes or name in self.traversal_indexes:
              try:
                  return self.proxies[name]
              except KeyError:
                  self.proxies[name] = ElementProxy(self, name)
                  return self.proxies[name]
          else:  # child not found in the indexes dictionary (e.g. msh_9.message_code, msh_9.msh_9_1)
              child_name = self._find_name(name)
              if child_name is not None:
                  try:
                      return self.proxies[child_name]
                  except KeyError:
                      self.proxies[child_name] = ElementProxy(self, child_name)
                      return self.proxies[child_name]
docs: Return an instance of :class:`ElementProxy <hl7apy.core.ElementProxy>` containing the children found
          having the given name
  
          :type name: ``str``
          :param name: the name of the children (e.g. PID)
  
          :return: an instance of :class:`ElementProxy <hl7apy.core.ElementProxy>` containing the results