4. If it's a new route, it connects by building either a direct socket connection, a TLS tunnel (for HTTPS over an HTTP proxy), or a direct TLS connection. It does TLS handshakes as necessary. This step may be retried for tunnel challenges and TLS handshake failures.
 5. It sends the HTTP request and reads the response.

/**
 * Reads a stream of [RFC 2046][rfc_2046] multipart body parts. Callers read parts one-at-a-time
 * until [nextPart] returns null. After calling [nextPart] any preceding parts should not be read.
 *
 * Typical use loops over the parts in sequence:
 *
 * ```kotlin
 * val response: Response = call.execute()
 * val multipartReader = MultipartReader(response.body!!)
 *
 * multipartReader.use {
 *   while (true) {

 *  Fix: Don't crash when a fast fallback call has both a deferred connection and a held connection.
 *  Fix: `OkHttpClient` no longer implements `Cloneable`. It never should have; the class is
    immutable. This is left over from OkHttp 2.x (!) when that class was mutable. We're using the
    5.x upgrade as an opportunity to remove very obsolete APIs.

    connections for HTTP/1.x. With this update the connection pool manages both
    idle and active connections for everything. OkHttp now detects and warns on
    connections that were allocated but never released, and will enforce HTTP/2
    stream limits. This update also fixes `Call.cancel()` to not do I/O on the
    calling thread.
 *  Fix: Don't log gzipped data in the logging interceptor.

        .build();
    try (Response response = client.newCall(request).execute()) {
      String responseSource = response.networkResponse() != null ? ("(network: "
          + response.networkResponse().code()
          + " over "
          + response.protocol()
          + ")") : "(cache)";
      int responseCode = response.code();

      System.out.printf("%03d: %s %s%n", responseCode, url, responseSource);

  //
  // Certain operations (like SYN_STREAM) need to synchronize on both the frameWriter (to do
  // blocking I/O) and this (to create streams). Such operations must synchronize on 'this' last.
  // This ensures that we never wait for a blocking operation while holding 'this'.

  /** True if this peer initiated the connection. */
  internal val client: Boolean = builder.client

  /** User code to run in response to incoming streams or settings. */

**Network Interceptors**

 * Able to operate on intermediate responses like redirects and retries.
 * Not invoked for cached responses that short-circuit the network.
 * Observe the data just as it will be transmitted over the network.
 * Access to the `Connection` that carries the request.

### Rewriting Requests

     * * [h2 with prior knowledge(cleartext only)][rfc_7540_34]
     *
     * **This is an evolving set.** Future releases include support for transitional
     * protocols. The http/1.1 transport will never be dropped.
     *
     * If multiple protocols are specified, [ALPN][alpn] will be used to negotiate a transport.
     * Protocol negotiation is only attempted for HTTPS URLs.
     *

            sameSite = attributeValue
          }
        }

        pos = attributePairEnd + 1
      }

      // If 'Max-Age' is present, it takes precedence over 'Expires', regardless of the order the two
      // attributes are declared in the cookie string.
      if (deltaSeconds == Long.MIN_VALUE) {
        expiresAt = Long.MIN_VALUE
      } else if (deltaSeconds != -1L) {

import org.junit.jupiter.api.Test

/**
 * Access every type, function, and property from Kotlin to defend against unexpected regressions in
 * 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",