Headers.headersOf(
        "cache-control",
        "no-cache",
        "cache-control",
        "no-store",
        "user-agent",
        "OkHttp",
      )
    val headerMap = headers.toMultimap()
    assertThat(headerMap["cache-control"]!!.size).isEqualTo(2)
    assertThat(headerMap["user-agent"]!!.size).isEqualTo(1)
  }

  @Test fun toMultimapUsesCanonicalCase() {
    val headers =

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterEntries(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredEntrySetMultimap<K extends @Nullable Object, V extends @Nullable Object>

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.List;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(ListMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeyListMultimap<K extends @Nullable Object, V extends @Nullable Object>

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeySetMultimap<K extends @Nullable Object, V extends @Nullable Object>

## Пример атаки { #example-attack }

Представьте, что вы сделали способ запускать локального ИИ-агента.

Он предоставляет API по адресу

```
http://localhost:8000/v1/agents/multivac
```

Есть также фронтенд по адресу

```
http://localhost:8000
```

/// tip | Совет

Обратите внимание, что у обоих один и тот же хост.

///

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterEntries(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredEntrySetMultimap<K extends @Nullable Object, V extends @Nullable Object>

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;
import java.util.Map.Entry;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link Multimaps#filterKeys(SetMultimap, Predicate)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class FilteredKeySetMultimap<K extends @Nullable Object, V extends @Nullable Object>

## Ejemplo de ataque { #example-attack }

Imagina que construyes una forma de ejecutar un agente de IA local.

Provee un API en

```
http://localhost:8000/v1/agents/multivac
```

También hay un frontend en

```
http://localhost:8000
```

/// tip | Consejo

Ten en cuenta que ambos tienen el mismo host.

///

FIELD com.google.common.collect.AbstractMultimap.values com.google.common.collect.LinkedListMultimap.get.$
FIELD com.google.common.collect.AbstractMultimap.values com.google.common.collect.Multimaps.MapMultimap.get.$
FIELD com.google.common.collect.AbstractMultiset.entrySet com.google.common.collect.FilteredEntryMultimap.Keys.entrySet.$
FIELD com.google.common.collect.ConcurrentHashMultiset.countMap

这种攻击主要在以下情况下相关：

- 应用在本地（如 `localhost`）或内网中运行
- 且应用没有任何认证，假定来自同一网络的请求都可信。

## 攻击示例 { #example-attack }

假设你构建了一个本地运行的 AI 代理。

它提供了一个 API，地址为

```
http://localhost:8000/v1/agents/multivac
```

另有一个前端，地址为

```
http://localhost:8000
```

/// tip | 提示

注意它们的主机相同。

///

之后，你可以通过前端让该 AI 代理替你执行操作。

由于它在本地运行、而非暴露在开放的互联网，你决定不配置任何认证，只信任对本地网络的访问。