assertThat(fooReference1).isNotSameInstanceAs(fooReference2);

    assertThat(mapCache.put(fooReference1, "bar")).isNull();
    assertThat(mapCache.get(fooReference1)).isEqualTo("bar"); // ensure first reference is cached
    assertThat(mapCache.remove(fooReference2)).isEqualTo("bar");
    assertThat(mapCache.get(fooReference1)).isNull();
  }

    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());
  }

  public void testCreateWithSize() {
    Multiset<String> multiset = LinkedHashMultiset.create(50);
    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());

    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);

    map.remove("foo");
    assertThat(map.entrySet())
        .containsExactly(immutableEntry("bar", 2), immutableEntry("quux", 3))
        .inOrder();
  }

  public void testInsertionOrderAfterRemoveMiddle() {
    BiMap<String, Integer> map = HashBiMap.create();
    map.put("foo", 1);
    map.put("bar", 2);
    map.put("quux", 3);

foo.txt foo bar.txt bar...

    map.put("bar", 4);
    assertEquals("[bar=1, foo=2, bar=3, bar=4]", map.entries().toString());
    assertThat(map.keys()).containsExactly("bar", "foo", "bar", "bar").inOrder();
    map.keys().remove("bar"); // bar is no longer the first key!
    assertEquals("{foo=[2], bar=[3, 4]}", map.toString());
  }

  public void testLinkedValues() {
    Multimap<String, Integer> map = create();
    map.put("bar", 1);
    map.put("foo", 2);

    multimap.put("foo", 1);
    multimap.put("foo", 2);
    multimap.put("bar", 3);
    multimap.trimToSize();
    assertEquals(3, multimap.size());
    assertThat(multimap.get("foo")).containsExactly(1, 2).inOrder();
    assertThat(multimap.get("bar")).contains(3);
  }

    assertEquals(Arrays.asList(4, 5), multimap.get("bar"));
    assertEquals(6, multimap.size());
  }

  public void testBuilderPutAllMultimapWithDuplicates() {
    Multimap<String, Integer> toPut = LinkedListMultimap.create();
    toPut.put("foo", 1);
    toPut.put("bar", 4);
    toPut.put("foo", 2);
    toPut.put("foo", 1);
    toPut.put("bar", 5);

 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the
 * resulting XML document is parsed, the parser API will return this text as the original literal
 * string {@code "Foo<Bar>"}.
 *
 * <p>A {@code CharEscaper} instance is required to be stateless, and safe when used concurrently by

    assertThat(headers.values("foo")).containsExactly("bar", "baz", "bak")
    assertThat(headers.values("key")).containsExactly("value")
    assertThat(headers.values("ping")).containsExactly("pong")
    assertThat(headers.values("kit")).containsExactly("kat")
  }

  @Test fun addThrowsOnEmptyName() {
    assertFailsWith<IllegalArgumentException> {
      Headers.Builder().add(": bar")
    }

⤴️, ⏮️ 📛 💖:

```
http://localhost:8000/items/?q=foo&q=bar
```

👆 🔜 📨 💗 `q` *🔢 🔢'* 💲 (`foo` & `bar`) 🐍 `list` 🔘 👆 *➡ 🛠️ 🔢*, *🔢 🔢* `q`.

, 📨 👈 📛 🔜:

```JSON
{
  "q": [
    "foo",
    "bar"
  ]
}
```

/// tip

📣 🔢 🔢 ⏮️ 🆎 `list`, 💖 🖼 🔛, 👆 💪 🎯 ⚙️ `Query`, ⏪ ⚫️ 🔜 🔬 📨 💪.

///