.Thread!: ClassType
.Thread!.name: Str
.Thread!.daemon: Bool
.Thread!.ident: Nat or NoneType # TODO: Pos or NoneType
.Thread!.native_id: Nat or NoneType
.Thread!.start!: (self: .Thread!) => NoneType
.Thread!.run!: (self: .Thread!) => NoneType
.Thread!.join!: (self: .Thread!, timeout := Nat or NoneType) => NoneType
.Thread!.is_alive: (self: .Thread!) -> Bool

.Local! = 'local': ClassType

.Lock!: ClassType
.RLock!: ClassType
.Condition!: ClassType
.Semaphore!: ClassType
.BoundedSemaphore!: ClassType
.Event!: ClassType
.Timer!: ClassType
.Barrier!: ClassType
.BrokenBarrierError: ClassType

.active_count!: () => Nat