code: def _find_name(self, name):
          
          name = name.upper()
          element = self.element.find_child_reference(name)
          return element['name'] if element is not None else None
docs: Find the reference of a child having the given name
  
          :type name: ``str``
          :param name: the child name (e.g. PID)
  
          :return: the element structure (see :func:`load_reference <hl7apy.load_reference>`) or ``None`` if the
              element has not been found