defaultDelay: Int,
  ): Int {
    val header = userResponse.header("Retry-After") ?: return defaultDelay

    // https://tools.ietf.org/html/rfc7231#section-7.1.3
    // currently ignores a HTTP-date, and assumes any non int 0 is a delay
    if (header.matches("\\d+".toRegex())) {
      return Integer.valueOf(header)
    }
    return Integer.MAX_VALUE
  }

  companion object {
    /**

      --proxy localhost:8888 \
      --proxytunnel \
      http://squareup.com/robots.txt
    ```

 *  Fix: Support executing OkHttp on kotlin-stdlib versions as old as 1.4. The library still builds
    on up-to-date Kotlin releases (1.6.21) but no longer needs that version as a runtime dependency.
    This should make it easier to use OkHttp in Gradle plugins.

    This could have corrupted requests where multiple headers had the same name,
    as in cookies.
 *  Fix: Reject bad characters in the URL hostname. Previously characters like
    `\0` would cause a late crash when building the request.
 *  Fix: Allow interceptors to change the request method.
 *  Fix: Don’t use the request's `User-Agent` or `Proxy-Authorization` when

    private var servedDate: Date? = null
    private var servedDateString: String? = null

    /** The last modified date of the cached response, if known. */
    private var lastModified: Date? = null
    private var lastModifiedString: String? = null

    /**
     * The expiration date of the cached response, if known. If both this field and the max age are

OkHttp attempts to balance two competing concerns:

 * **Connectivity** to as many hosts as possible. That includes advanced hosts that run the latest versions of [boringssl](https://boringssl.googlesource.com/boringssl/) and less out of date hosts running older versions of [OpenSSL](https://www.openssl.org/).
 * **Security** of the connection. This includes verification of the remote webserver with certificates and the privacy of data exchanged with strong ciphers.

    assertThat(decoded).isEqualTo(date("2049-12-31T23:59:59.000+0000").time)
  }

  @Test fun `time before 1950 uses GENERALIZED_TIME`() {
    val generalizedTimeDer = "180f31393439313233313233353935395a".decodeHex()

    val decoded = CertificateAdapters.time.fromDer(generalizedTimeDer)
    val encoded = CertificateAdapters.time.toDer(decoded)

    assertThat(decoded).isEqualTo(date("1949-12-31T23:59:59.000+0000").time)

          if (!response.isSuccessful) throw IOException("Unexpected code $response")

          println("Server: ${response.header("Server")}")
          println("Date: ${response.header("Date")}")
          println("Vary: ${response.headers("Vary")}")
        }
      }
    ```

=== ":material-language-java: Java"
    ```java

      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without

 * your OkHttp library can break connectivity to certain web servers! But it’s a necessary annoyance
 * because the TLS ecosystem is dynamic and staying up to date is necessary to stay secure. See
 * [OkHttp's TLS Configuration History][tls_history] to track these changes.
 *
 * [tls_history]: https://square.github.io/okhttp/tls_configuration_history/
 */

      Header("content-language", ""),
      Header("content-length", ""),
      Header("content-location", ""),
      Header("content-range", ""),
      Header("content-type", ""),
      Header("cookie", ""),
      Header("date", ""),
      Header("etag", ""),
      Header("expect", ""),
      Header("expires", ""),
      Header("from", ""),
      Header("host", ""),
      Header("if-match", ""),
      Header("if-modified-since", ""),