1	import Base
2	
3	# Preserves the first cleanup failure and otherwise returns the final result.
4	def combine(
5	  a,
6	  -E: Kind(a),
7	  first: Result<a, &1, E, Unit>,
8	  second: Result<a, &1, E, Unit>
9	) -> Result<a, &1, E, Unit>:
10	  match first:
11	    case Fail{error}: Fail{error}
12	    case Done{Unit{}}: second