write/flush after response handler has returned.
```

```
λ git cherry-pick 4f3317effea38c203c358af9cb5ce3c0e4173976
```

import okhttp3.internal.http.RealInterceptorChain
import okhttp3.internal.http.RecordingProxySelector
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.internal.TlsUtil.localhost

/**
 * OkHttp is usually tested with functional tests: these use public APIs to confirm behavior against
 * MockWebServer. In cases where logic is particularly tricky, we use unit tests. This class makes
 * it easy to get sample values to use in such tests.

   *
   * <p><b>Warning:</b> This method will produce different output than most other languages do when
   * running on the equivalent input. For cross-language compatibility, use {@link #putString},
   * usually with a charset of UTF-8. For other use cases, use {@code putUnencodedChars}.
   *
   * @since 15.0 (since 11.0 as putString(CharSequence))
   */
  @CanIgnoreReturnValue

//    .enableImplicitConfigurationParameters(false)
      .selectors(selectors)
      .build()
  return request
}

/**
 * Flattens a test filter into a list of specific test descriptors, usually individual method in a
 * test class annotated with @Test.
 */
fun findTests(selectors: List<DiscoverySelector>): List<TestDescriptor> {
  val request: LauncherDiscoveryRequest = buildRequest(selectors)

  public long loadCount() {
    return saturatedAdd(loadSuccessCount, loadExceptionCount);
  }

  /**
   * Returns the number of times {@link Cache} lookup methods have successfully loaded a new value.
   * This is usually incremented in conjunction with {@link #missCount}, though {@code missCount} is
   * also incremented when an exception is encountered during cache loading (see {@link

  public long loadCount() {
    return saturatedAdd(loadSuccessCount, loadExceptionCount);
  }

  /**
   * Returns the number of times {@link Cache} lookup methods have successfully loaded a new value.
   * This is usually incremented in conjunction with {@link #missCount}, though {@code missCount} is
   * also incremented when an exception is encountered during cache loading (see {@link

    /**
     * The checksum algorithm.
     */
    interface ChecksumAlgorithm {
        /**
         * Returns the algorithm name, usually used as key, never {@code null} value. The name is a standard name of
         * algorithm (if applicable) or any other designator that is algorithm commonly referred with. Example: "SHA-1".
         */
        @Nonnull

main channel of communication for contributors.  
There are some guidelines which will make applying PRs easier for us:
+ Create a topic branch from where you want to base your work (this is usually the master branch).
  Push your changes to a topic branch in your fork of the repository.
+ Make commits of logical units.
+ Respect the original code style: by using the same [codestyle][code-style],

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Provides utility methods for working with resources in the classpath. Note that even though these
 * methods use {@link URL} parameters, they are usually not appropriate for HTTP or other
 * non-classpath resources.
 *
 * @author Chris Nokleberg
 * @author Ben Yu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible

 * limitations under the License.
 */
package okhttp3

import okio.ByteString

/**
 * A non-blocking interface to a web socket. Use the [factory][WebSocket.Factory] to create
 * instances; usually this is [OkHttpClient].
 *
 * ## Web Socket Lifecycle
 *
 * Upon normal operation each web socket progresses through a sequence of states:
 *