fetchTick :: IO (Maybe Tick)
fetchTick = do
  outer <- tickerResult
  case outer of
    Left _ -> return Nothing
    Right out ->
      case HM.lookup "USD" out of
        Nothing -> return Nothing
        Just p -> return $ l2t p
fetchTick :: IO (Maybe Tick)
fetchTick = do
  outer <- tickerResult
  case outer of
    Left _ -> return Nothing
    Right out ->
      case HM.lookup "USD" out of
        Nothing -> return Nothing
        Just p -> return $ l2t p
fetchTick = do
  outer <- tickerResult
  case outer of
    Left _ -> return Nothing
    Right out ->
      case HM.lookup "USD" out of
        Nothing -> return Nothing
        Just p -> return $ l2t p