### CORS preflight requests { #cors-preflight-requests }

These are any `OPTIONS` request with `Origin` and `Access-Control-Request-Method` headers.

In this case the middleware will intercept the incoming request and respond with appropriate CORS headers, and either a `200` or `400` response for informational purposes.

### Simple requests { #simple-requests }

    val next = copy(index = index + 1, request = request)
    val interceptor = interceptors[index]

    @Suppress("USELESS_ELVIS")
    val response =
      interceptor.intercept(next) ?: throw NullPointerException(
        "interceptor $interceptor returned null",
      )

    if (exchange != null) {
      check(index + 1 >= interceptors.size || next.calls == 1) {

   * <p>The implementation deviates from the {@code ExecutorService} specification with regards to
   * the {@code shutdownNow} method. First, "best-effort" with regards to canceling running tasks is
   * implemented as "no-effort". No interrupts or other attempts are made to stop threads executing
   * tasks. Second, the returned list will always be empty, as any submitted task is considered to

import okio.buffer

/** This is the last interceptor in the chain. It makes a network call to the server. */
object CallServerInterceptor : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
    val realChain = chain as RealInterceptorChain
    val exchange = realChain.exchange!!
    val request = realChain.request
    val requestBody = request.body

   * If the timeout expires, not only will the output future finish, but also the input future
   * ({@code this}) will be cancelled and interrupted.
   *
   * @param timeout when to time out the future
   * @param scheduledExecutor The executor service to enforce the timeout.
   * @since 33.4.0 (but since 28.0 in the JRE flavor)
   */
  @J2ktIncompatible

/** Serves requests from the cache and writes responses to the cache. */
class CacheInterceptor(
  internal val call: RealCall,
  internal val cache: Cache?,
) : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
    val cacheCandidate = cache?.get(chain.request().requestForCache())

    val now = System.currentTimeMillis()

- All versioned buckets maintain the same order for "versions" for each object after being decommissioned to the other pools.
- A pool interrupted during the decommission process, such as for a cluster restart, resumes from where it left off.

## How to decommission a pool

```
λ mc admin decommission start alias/ http://minio{1...2}/data{1...4}
```

   * {@code setUpRan} parameter is set true by the {@code setUp} that every test case is supposed to
   * have registered, and set false by the {@code tearDown}. We use a dynamic proxy to intercept all
   * of the {@code Map} method calls and check that {@code setUpRan} is true.
   */
  private static class CheckSetUpHashMapGenerator extends WrappedHashMapGenerator {
    private final AtomicBoolean setUpRan;

 * [IOException] if the call was canceled.
 */
class RetryAndFollowUpInterceptor(
  private val client: OkHttpClient,
) : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {
    val realChain = chain as RealInterceptorChain
    var request = chain.request
    val call = realChain.call
    var followUpCount = 0
    var priorResponse: Response? = null

   * {@code setUpRan} parameter is set true by the {@code setUp} that every test case is supposed to
   * have registered, and set false by the {@code tearDown}. We use a dynamic proxy to intercept all
   * of the {@code Map} method calls and check that {@code setUpRan} is true.
   */
  private static class CheckSetUpHashMapGenerator extends WrappedHashMapGenerator {
    private final AtomicBoolean setUpRan;