library test /*isNonNullableByDefault*/;
import self as self;
import "dart:core" as core;

static method test1(core::List<core::int> o) → dynamic {
  core::Iterable<Null> y = o.{core::Iterable::map}<Null>((core::int x) → Null {}){((core::int) → Null) → core::Iterable<Null>};
  core::Iterable<core::int?> z = y;
}
static method main() → dynamic {}