rtupLookup ::
       ColumnName    -- ^ ColumnName key
    -> RTuple        -- ^ Input RTuple
    -> Maybe RDataType     -- ^ Output value
rtupLookup =  HM.lookup
rtupLookup ::
       ColumnName    -- ^ ColumnName key
    -> RTuple        -- ^ Input RTuple
    -> Maybe RDataType
rtupLookup =  HM.lookup
rtupLookup =  HM.lookup