getLabel :: Monad m => MkPNMonad m value [String]
    getLabel = state op
        where op mkpn = (mkpnLabelStack mkpn, mkpn)
getLabel :: Monad m => MkPNMonad m value [String]
getLabel = state op
        where op mkpn = (mkpnLabelStack mkpn, mkpn)
getLabel = state op
        where op mkpn = (mkpnLabelStack mkpn, mkpn)