def METHOD_NAME(self, data, tags, members):
    capture_tags = {}
    keys = tags.keys()
    err = []
    # relation[power=transformer]
    if ('power' in keys):
        match = False
        if not match:
            capture_tags = {}
            try: match = ((mapcss._tag_capture(capture_tags, 0, tags, 'power') == mapcss._value_capture(capture_tags, 0, 'transformer')))
            except mapcss.RuleAbort: pass
        if match:
            # -osmoseTags:list("geom")
            # -osmoseItemClassLevel:"9100/91001/2"
            # throwWarning:tr("Power Transformers should always be on a node")
            err.append({'class': 91001, 'subclass': 0, 'text': mapcss.tr('Power Transformers should always be on a node')})
    return err