* limitations under the License.
 */
package okhttp3

import java.io.IOException
import java.util.concurrent.TimeUnit

/**
 * Records received HTTP responses so they can be later retrieved by tests.
 */
class RecordingCallback : Callback {
  private val responses = mutableListOf<RecordedResponse>()

  @Synchronized
  override fun onFailure(
    call: Call,
    e: IOException,
  ) {

## Follow-up Requests

When your requested URL has moved, the webserver will return a response code like `302` to indicate the document’s new URL. OkHttp will follow the redirect to retrieve a final response.

When you request a URL with OkHttp, here's what it does:

 1. It uses the URL and configured OkHttpClient to create an **address**. This address specifies how we'll connect to the webserver.
 2. It attempts to retrieve a connection with that address from the **connection pool**.

    OkHttpClient client = new OkHttpClient();

    // Create request for remote resource.
    Request request = new Request.Builder()
        .url(ENDPOINT)
        .build();

    // Execute the request and retrieve the response.
    try (Response response = client.newCall(request).execute()) {
      // Deserialize HTTP response to concrete type.
      ResponseBody body = response.body();