.build()

    client.newCall(request).enqueue(
      object : Callback {
        override fun onFailure(
          call: Call,
          e: IOException,
        ) {
          e.printStackTrace()
        }

        override fun onResponse(
          call: Call,
          response: Response,
        ) {
          response.use {

            "No mapping between account names and security IDs was done.", "The security ID structure is invalid.",
            "All pipe instances are busy.", "All pipe instances are busy.", "The pipe state is invalid.", "All pipe instances are busy.",
            "No process is on the other end of the pipe.", "The pipe is being closed.",

            .build()

        val exchange = call.interceptorScopedExchange
        val followUp = followUpRequest(response, exchange)

        if (followUp == null) {
          if (exchange != null && exchange.isDuplex) {
            call.timeoutEarlyExit()
          }
          closeActiveExchange = false
          call.eventListener.followUpDecision(call, response, null)
          return response
        }

	public abstract fun cancel ()V
	public static fun enqueue (Lokhttp3/Call;Lokhttp3/sse/EventSourceListener;)Lokhttp3/sse/EventSource;
	public static fun process (Lokhttp3/Response;Lokhttp3/sse/EventSourceListener;)V
	public abstract fun request ()Lokhttp3/Request;
}

public final class okhttp3/sse/EventSource$Companion {
	public final fun enqueue (Lokhttp3/Call;Lokhttp3/sse/EventSourceListener;)Lokhttp3/sse/EventSource;

 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current

const maxInt = int(^uint(0) >> 1)

// Bytes returns a slice of length b.Len() holding the unread portion of the buffer.
// The slice is valid for use only until the next buffer modification (that is,
// only until the next call to a method like [Buffer.Read], [Buffer.Write], [Buffer.Reset], or [Buffer.Truncate]).
// The slice aliases the buffer content at least until the next buffer modification,

    if (subjectGenerator == null) {
      throw new IllegalStateException("Call using() before createTestSuite().");
    }
    if (name == null) {
      throw new IllegalStateException("Call named() before createTestSuite().");
    }
    if (features == null) {
      throw new IllegalStateException("Call withFeatures() before createTestSuite().");
    }
  }

Actually, all (or most) of the web frameworks work in this same way.

You never call those functions directly. They are called by your framework (in this case, **FastAPI**).

        .url(server.url("/"))
        .post(AsyncRequestBody())
        .build()
    val call = client.newCall(request)
    call.timeout().timeout(250, TimeUnit.MILLISECONDS)
    assertFailsWith<IOException> {
      call.execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("timeout")
      assertTrue(call.isCanceled())
    }
  }

  @Test
  fun fullCallTimeoutDoesNotApplyOnceConnected() {

 * {@link UnsupportedOperationException} when they are not implemented. Most implementations should
 * support either all add operations or none of them, all removal operations or none of them, and if
 * and only if all of these are supported, the {@code setCount} methods as well.
 *
 * <p>A multiset uses {@link Object#equals} to determine whether two instances should be considered