To see the difference, imagine the following story about burgers:

### Concurrent Burgers { #concurrent-burgers }

You go with your crush to get fast food, you stand in line while the cashier takes the orders from the people in front of you. 😍

<img src="/img/async/concurrent-burgers/concurrent-burgers-01.png" class="illustration">

	public fun clone ()Lokhttp3/mockwebserver/MockResponse;
	public final fun getBody ()Lokio/Buffer;
	public final fun getBodyDelay (Ljava/util/concurrent/TimeUnit;)J
	public final fun getHeaders ()Lokhttp3/Headers;
	public final fun getHeadersDelay (Ljava/util/concurrent/TimeUnit;)J
	public final fun getHttp2ErrorCode ()I
	public final fun getPushPromises ()Ljava/util/List;

import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.lucene.search.TotalHits.Relation;
import org.codelibs.fess.entity.FacetInfo;

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.lang.ref.WeakReference;
import java.util.ConcurrentModificationException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.jspecify.annotations.Nullable;

/**
 * A builder of {@link ConcurrentMap} instances that can have keys or values automatically wrapped

<img src="/img/async/concurrent-burgers/concurrent-burgers-05.png" class="illustration">

기다리며 대화하는 동안, 때때로 여러분은 카운터에 표시되는 번호를 확인해 여러분 차례인지 봅니다.

그러다 어느 순간 마침내 여러분 차례가 됩니다. 여러분은 카운터에 가서 햄버거를 받고, 테이블로 돌아옵니다.

<img src="/img/async/concurrent-burgers/concurrent-burgers-06.png" class="illustration">

여러분과 짝사랑 상대는 햄버거를 먹으며 좋은 시간을 보냅니다. ✨

<img src="/img/async/concurrent-burgers/concurrent-burgers-07.png" class="illustration">

	public final fun status (Ljava/lang/String;)Lmockwebserver3/MockResponse$Builder;
	public final fun throttleBody (JJLjava/util/concurrent/TimeUnit;)Lmockwebserver3/MockResponse$Builder;
	public final fun trailers (Lokhttp3/Headers;)Lmockwebserver3/MockResponse$Builder;
	public final fun trailersDelay (JLjava/util/concurrent/TimeUnit;)Lmockwebserver3/MockResponse$Builder;

system by default adapts to the system speed and pauses up to '250ms' per object when the system has `max_io` number of concurrent requests. It is possible to adjust the `max_sleep` and `max_io` values thereby increasing the healing speed. The delays between each operation of the healer can be adjusted by the `mc admin config set alias/ heal max_sleep=1s` and maximum concurrent requests allowed before we start slowing things down can be configured with `mc admin config set alias/ heal max_io=30`...

- **Logging Abstraction** (`org.codelibs.core.log`) - Flexible logging system supporting JCL (Jakarta Commons Logging) and JUL (Java Util Logging)
- **Concurrent Utilities** (`org.codelibs.core.concurrent`) - Thread-safe collections and concurrency helpers using modern concurrent APIs
- **Crypto & Security** (`org.codelibs.core.crypto`, `org.codelibs.core.security`) - Basic cryptographic utilities, message digest operations, and secure random generation

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.Mockito;