getNumId :: Block -> Maybe Integer
getNumId (Div (_, _, kvs) _) =  liftM read $ lookup "num-id" kvs
getNumId :: Block -> Maybe Integer
getNumId (Div (_, _, kvs) _) =  liftM read $ lookup "num-id" kvs
getNumId (Div (_, _, kvs) _) =  liftM read $ lookup "num-id" kvs