func printTaskLocal<V>(
    _ key: TaskLocal<V>,
    _ expected: V? = nil,
    file: String = #file, line: UInt = #line
) -> V? {
  let value = key.get()
  print("\(key) (\(value)) at \(file):\(line)")
  if let expected = expected {
    assert("\(expected)" == "\(value)",
        "Expected [\(expected)] but found: \(value), at \(file):\(line)")
  }
  return expected
}
