upsertRTuple ::
           ColumnName  -- ^ key where the upset will take place
        -> RDataType   -- ^ new value
        -> RTuple      -- ^ input RTuple
        -> RTuple      -- ^ output RTuple
upsertRTuple cname newVal tupsrc = HM.insert cname newVal tupsrc
upsertRTuple ::
           ColumnName  -- ^ key where the upset will take place
        -> RDataType   -- ^ new value
        -> RTuple      -- ^ input RTuple
        -> RTuple
upsertRTuple cname newVal tupsrc = HM.insert cname newVal tupsrc
upsertRTuple cname newVal tupsrc = HM.insert cname newVal tupsrc