class MockWebServerExtension :
  BeforeEachCallback, AfterEachCallback, ParameterResolver, BeforeAllCallback, AfterAllCallback {
  private val ExtensionContext.resource: ServersForTest
    get() =
      getStore(namespace).getOrComputeIfAbsent(this.uniqueId) {
        ServersForTest()
      } as ServersForTest

  private class ServersForTest {
    private val servers = mutableMapOf<String, MockWebServer>()
    private var started = false