import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.ResponseBody
import okio.BufferedSource

class RealResponseBody(
  /**
   * Use a string to avoid parsing the content type until needed. This also defers problems caused
   * by malformed content types.
   */
  private val contentTypeString: String?,
  private val contentLength: Long,
  private val source: BufferedSource,
) : ResponseBody() {

    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }
    // Check for the characters mentioned in the WHATWG Host parsing spec:

 * Fix 1.5.0 regression where connections should not have been recycled.
 * Fix 1.5.0 regression where transparent Gzip was broken by attempting to
   recover from another I/O failure.
 * Fix problems where spdy/3.1 headers may not have been compressed properly.
 * Fix problems with spdy/3.1 and http/2 where the wrong window size was being
   used.
 * Fix 1.5.0 regression where conditional cache responses could corrupt the
   connection pool.

 * Transparent GZIP shrinks download sizes.
 * Response caching avoids the network completely for repeat requests.

OkHttp perseveres when the network is troublesome: it will silently recover from common connection
problems. If your service has multiple IP addresses, OkHttp will attempt alternate addresses if the
first connect fails. This is necessary for IPv4+IPv6 and services hosted in redundant data

   developers and others in the free software community to coordinate our efforts.

 * **Be pragmatic**: Questions are encouraged and should be asked early in the process to avoid
   problems later. Be thoughtful and considerate when seeking out the appropriate forum for your
   questions. Those who are asked should be responsive and helpful.

    connection takes more than 10 seconds to complete, you’ll need to adjust
    the timeouts manually.

 *  **OkHttp now rejects request headers that contain invalid characters.** This
    includes potential security problems (newline characters) as well as simple
    non-ASCII characters (including international characters and emoji).

 *  **Call canceling is more reliable.**  We had a bug where a socket being

    testSecureStreamingPost(TransferKind.FIXED_LENGTH)
  }

  @Test
  fun secureChunkedStreaming() {
    testSecureStreamingPost(TransferKind.CHUNKED)
  }

  /**
   * Users have reported problems using HTTPS with streaming request bodies.
   * http://code.google.com/p/android/issues/detail?id=12860
   */
  private fun testSecureStreamingPost(streamingMode: TransferKind) {

     * certificate is issued to `example.com` and the request is to `localhost`, the connection will
     * fail. Use a custom [HostnameVerifier] to ignore such problems.
     *
     * Other TLS features are still used but provide no security benefits in absence of the above
     * gaps. For example, an insecure TLS connection is capable of negotiating HTTP/2 with ALPN and

 * limitations under the License.
 */
package okhttp3

import okio.IOException

interface Callback {
  /**
   * Called when the request could not be executed due to cancellation, a connectivity problem or
   * timeout. Because networks can fail during an exchange, it is possible that the remote server
   * accepted the request before the failure.
   */
  fun onFailure(
    call: Call,
    e: IOException,
  )

If you're in a tricky situation and prepared to deal with the consequences, rewriting response headers is a powerful way to work around problems. For example, you can fix a server's misconfigured `Cache-Control` response header to enable better response caching:

```java
/** Dangerous interceptor that rewrites the server's cache-control header. */