Map.union: def of Base
Import: import Base
Lines 3050-3051 of Base/base.bend: https://jend.leeeet.dev/read.txt?path=Base/base.bend&start_line=3050&end_line=3051

import Base

def Map.union(a, -V: Kind(a), m: Map<a, V>, n: Map<a, V>) -> Map<a, V>:
  Map.from_list.go(a, V, Map.to_list(a, V, n), m)

Uses (3):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Map
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Map.from_list.go
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Map.to_list