Major Description
Ref: https://prestodb.io/docs/current/functions/map.html
Returns a map that applies function to each entry of map and transforms the values.
SELECT transform_values(MAP(ARRAY[], ARRAY[]), (k, v) -> v + 1); -- {}
SELECT transform_values(MAP(ARRAY [1, 2, 3], ARRAY [10, 20, 30]), (k, v) -> v + k); -- {1 -> 11, 2 -> 22, 3 -> 33}
SELECT transform_values(MAP(ARRAY [1, 2, 3], ARRAY ['a', 'b', 'c']), (k, v) -> k * k); -- {1 -> 1, 2 -> 4, 3 -> 9}
SELECT transform_values(MAP(ARRAY ['a', 'b'], ARRAY [1, 2]), (k, v) -> k || CAST(v as VARCHAR)); -- {a -> a1, b -> b2}
SELECT transform_values(MAP(ARRAY [1, 2], ARRAY [1.0, 1.4]), -- {1 -> one_1.0, 2 -> two_1.4}
(k, v) -> MAP(ARRAY[1, 2], ARRAY['one', 'two'])[k] || '_' || CAST(v AS VARCHAR));
