check(x509TrustManager == null)
      check(certificatePinner == CertificatePinner.DEFAULT)
    } else {
      checkNotNull(sslSocketFactoryOrNull) { "sslSocketFactory == null" }
      checkNotNull(certificateChainCleaner) { "certificateChainCleaner == null" }
      checkNotNull(x509TrustManager) { "x509TrustManager == null" }
    }
  }

  /** Prepares the [request] to be executed at some point in the future. */