val instant: Instant? = headers.getInstant("")
    val size: Int = headers.size
    val name: String = headers.name(0)
    val value: String = headers.value(0)
    val names: Set<String> = headers.names()
    val values: List<String> = headers.values("")
    val byteCount: Long = headers.byteCount()
    val builder: Headers.Builder = headers.newBuilder()

 * modern 4.0.x kotlin source-compatibility.
 */
@Suppress(
  "ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE",
  "UNUSED_ANONYMOUS_PARAMETER",
  "UNUSED_VALUE",
  "UNUSED_VARIABLE",
  "VARIABLE_WITH_REDUNDANT_INITIALIZER",
  "RedundantLambdaArrow",
  "RedundantExplicitType",
  "IMPLICIT_NOTHING_AS_TYPE_PARAMETER",
)
class KotlinSourceModernTest {
  @Test @Ignore