```java
class MetricsEventListener extends EventListener {
  private static final Factory FACTORY = new Factory() {
    @Override public EventListener create(Call call) {
      if (Math.random() < 0.10) {
        return new MetricsEventListener(call);
      } else {
        return EventListener.NONE;
      }
    }
  };

  ...
}
```

### Events with Failures

    return try {
      // Attempt to get the trust manager from an OpenJDK socket factory. We attempt this on all
      // platforms in order to support Robolectric, which mixes classes from both Android and the
      // Oracle JDK. Note that we don't support HTTP/2 or other nice features on Robolectric.
      val sslContextClass = Class.forName("sun.security.ssl.SSLContextImpl")

     *
     * ## Upstream
     *
     * In this case the current thread is assigned as the upstream reader. We read bytes from
     * upstream and copy them to both the file and to the buffer. Finally we release the upstream
     * reader lock and return the new bytes.
     *
     * ## The file
     *
     * In this case we copy bytes from the file to the [sink].
     *

import assertk.assertThat
import assertk.assertions.containsExactly
import assertk.assertions.isCloseTo
import assertk.assertions.isEqualTo
import assertk.assertions.isNull
import assertk.assertions.matches
import java.math.BigInteger
import java.security.KeyFactory
import java.security.spec.PKCS8EncodedKeySpec
import java.security.spec.X509EncodedKeySpec
import java.util.concurrent.TimeUnit
import okhttp3.testing.PlatformRule

    private var keySize: Int = 0

    init {
      ecdsa256()
    }

    /**
     * Sets the certificate to be valid in ```[notBefore..notAfter]```. Both endpoints are specified
     * in the format of [System.currentTimeMillis]. Specify -1L for both values to use the default
     * interval, 24 hours starting when the certificate is created.
     */
    fun validityInterval(
      notBefore: Long,

import okio.ByteString.Companion.encodeUtf8
import okio.ByteString.Companion.toByteString
import okio.FileSystem
import okio.ForwardingSink
import okio.ForwardingSource
import okio.Path
import okio.Path.Companion.toOkioPath
import okio.Sink
import okio.Source
import okio.buffer

/**
 * Caches HTTP and HTTPS responses to the filesystem so they may be reused, saving time and
 * bandwidth.
 *

        .cookieJar(JavaNetCookieJar(cookieManager))
        .build()
    val urlWithIpAddress = urlWithIpAddress(server, "/path/foo")
    server.enqueue(
      MockResponse.Builder()
        .addHeader(
          "Set-Cookie: a=android; " +
            "expires=Fri, 31-Dec-9999 23:59:59 GMT; " +
            "path=/path; " +
            "domain=${urlWithIpAddress.host}; " +
            "secure",
        )
        .build(),
    )

      val pathEnd = requestLine.indexOf(' ', methodEnd + 1)
      this.method = requestLine.substring(0, methodEnd)
      var path = requestLine.substring(methodEnd + 1, pathEnd)
      if (!path.startsWith("/")) {
        path = "/"
      }
      this.path = path

      val scheme = if (socket is SSLSocket) "https" else "http"
      val localPort = socket.localPort
      val hostAndPort =

    level = DeprecationLevel.ERROR,
  )
  fun method(): String = method

  @JvmName("-deprecated_path")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "path"),
    level = DeprecationLevel.ERROR,
  )
  fun path(): String = path

  @JvmName("-deprecated_headers")
  @Deprecated(
    message = "moved to val",

/** Impersonate TCP-style ServerSocketFactory over UNIX domain sockets. */
public final class UnixDomainServerSocketFactory extends ServerSocketFactory {
  private final File path;

  public UnixDomainServerSocketFactory(File path) {
    this.path = path;
  }

  @Override public ServerSocket createServerSocket() throws IOException {
    return new UnixDomainServerSocket();
  }