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

static method main() → dynamic {
  core::Object? a;
  core::Object? b;
  return block {
    final core::Set<core::Object?> #t1 = new col::_CompactLinkedHashSet::•<core::Object?>();
    #t1.{core::Set::add}{Invariant}(let final core::Object? #t2 = a in #t2 == null ?{core::Object?} b : #t2{core::Object}){(core::Object?) → core::bool};
  } =>#t1;
}