(like HTTP/2).

URLs that share the same address may also share the same underlying TCP socket connection. Sharing a connection has substantial performance benefits: lower latency, higher throughput (due to [TCP slow start](https://www.igvita.com/2011/10/20/faster-web-vs-tcp-slow-start/)) and conserved battery. OkHttp uses a [ConnectionPool](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-pool/) that automatically reuses HTTP/1.x connections and multiplexes HTTP/2 connections....

import org.junit.jupiter.api.Assertions.fail
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension

@Tag("Slowish")
class DnsOverHttpsTest {
  @RegisterExtension
  val platform = PlatformRule()

  @StartStop
  private val server = MockWebServer()

  private lateinit var dns: Dns
  private val cacheFs = FakeFileSystem()

testing everything. You can even copy & paste HTTP responses from your real web
server to create representative test cases. Or test that your code survives in
awkward-to-reproduce situations like 500 errors or slow-loading responses.


### Example

Use MockWebServer the same way that you use mocking frameworks like
[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.

    assertTrue(multimap.containsEntry("bar", 3));
    assertEquals(4, (int) entrya.getValue());
    assertEquals(3, (int) entryb.getValue());
  }

  @GwtIncompatible // unreasonably slow
  public void testEntriesIteration() {
    List<Entry<String, Integer>> addItems =
        ImmutableList.of(
            immutableEntry("foo", 99), immutableEntry("foo", 88), immutableEntry("bar", 77));

import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Tag
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension
import org.junitpioneer.jupiter.RetryingTest

@Tag("Slowish")
class EventSourceHttpTest {
  @RegisterExtension
  val platform = PlatformRule()

  @StartStop
  private val server = MockWebServer()

  @RegisterExtension
  val clientTestRule = OkHttpClientTestRule()

          }.replace("(.*)\\.kt".toRegex()) { mr ->
            mr.groupValues[1].replace('/', '.') + "Kt"
          }
      }.sorted()
  }
}

@Disabled("Don't run by default")
@Tag("Slow")
class AllMainsTest {
  @ParameterizedTest
  @ArgumentsSource(MainTestProvider::class)
  fun runMain(className: String) {
    val mainMethod =
      Class
        .forName(className)
        .methods

      assertEquals(BigIntegerMath.sqrt(x, floorWasOdd ? HALF_UP : HALF_DOWN), halfEven);
    }
  }

  @GwtIncompatible // TODO
  @AndroidIncompatible // slow
  public void testDivNonZero() {
    for (BigInteger p : NONZERO_BIGINTEGER_CANDIDATES) {
      for (BigInteger q : NONZERO_BIGINTEGER_CANDIDATES) {
        for (RoundingMode mode : ALL_SAFE_ROUNDING_MODES) {

So, during that time, the computer can go and do some other work, while "slow-file" 📝 finishes.

 *   }
 * }
 * ```
 *
 * Note that [nextPart] will skip any unprocessed data from the preceding part. If the preceding
 * part is particularly large or if the underlying source is particularly slow, the [nextPart] call
 * may be slow!
 *
 * Closing a part **does not** close this multipart reader; callers must explicitly close this with
 * [close].
 *
 * [rfc_2046]: http://www.ietf.org/rfc/rfc2046.txt
 */
class MultipartReader

         * This avoids out-of-control memory consumption, and it keeps the cache from growing so
         * large that doing the lookup is noticeably slower than redoing the work would be.
         *
         * Ideally we'd have a real eviction policy, but until we see a problem in practice, I hope