languages2_1 := []*Language{
		{Code: "language-slice-replace-1-1", Name: "language-slice-replace-1-1"},
		{Code: "language-slice-replace-1-2", Name: "language-slice-replace-1-2"},
	}
	languages2_2 := []*Language{
		{Code: "language-slice-replace-2-1", Name: "language-slice-replace-2-1"},
		{Code: "language-slice-replace-2-2", Name: "language-slice-replace-2-2"},
	}

	)

	AssertAssociationCount(t, users, "Pets", 10, "After Append")

	// Replace -> same as append
	DB.Model(&users).Association("Pets").Replace(
		[]*Pet{{Name: "pet-slice-replace-1-1"}, {Name: "pet-slice-replace-1-2"}},
		[]*Pet{{Name: "pet-slice-replace-2-1"}, {Name: "pet-slice-replace-2-2"}},
		&Pet{Name: "pet-slice-replace-3"},
	)

	AssertAssociationCount(t, users, "Pets", 5, "After Append")

	// Delete

      """
      |--simple boundary
      |
      |abcd
      |--simple boundary
      |
      |efgh
      |--simple boundary--
      """.trimMargin()
        .replace("\n", "\r\n")
        .replace(Regex("(?m)abcd\r\n"), "abcd\n")

    val parts =
      MultipartReader(
        boundary = "simple boundary",
        source = Buffer().writeUtf8(multipart),
      )

		t.Fatalf("Preload many2many relations")
	}

	// Replace
	tag5 := &Tag{Locale: "ZH", Value: "tag5"}
	tag6 := &Tag{Locale: "ZH", Value: "tag6"}
	DB.Model(&blog).Association("Tags").Replace(tag5, tag6)
	var tags2 []Tag
	DB.Model(&blog).Association("Tags").Find(&tags2)
	if !compareTags(tags2, []string{"tag5", "tag6"}) {
		t.Fatalf("Should find 2 tags after Replace")
	}

	if DB.Model(&blog).Association("Tags").Count() != 2 {

        // don't compareAndSet a zero
        if (map.replace(key, atomic, new AtomicLong(newValue))) {
          return 0L;
        }
        // atomic replaced
        continue;
      }

      return oldValue;
    }
  }

  /**
   * If {@code (key, expectedOldValue)} is currently in the map, this method replaces {@code

    }
  }

  @Test
  fun singlePart() {
    val expected =
      """
      |--123
      |
      |Hello, World!
      |--123--
      |
      """.trimMargin().replace("\n", "\r\n")
    val body =
      MultipartBody.Builder("123")
        .addPart("Hello, World!".toRequestBody(null))
        .build()
    assertThat(body.boundary).isEqualTo("123")

    assertNull(map.putIfAbsent(three, one));
    assertSame(one, map.get(three));
    assertSame(two, map.replace(one, three));
    assertSame(three, map.get(one));
    assertFalse(map.replace(one, two, three));
    assertSame(three, map.get(one));
    assertTrue(map.replace(one, three, two));
    assertSame(two, map.get(one));
    assertEquals(3, map.size());

    map.clear();

    assertNull(map.putIfAbsent(three, one));
    assertSame(one, map.get(three));
    assertSame(two, map.replace(one, three));
    assertSame(three, map.get(one));
    assertFalse(map.replace(one, two, three));
    assertSame(three, map.get(one));
    assertTrue(map.replace(one, three, two));
    assertSame(two, map.get(one));
    assertEquals(3, map.size());

    map.clear();

        assertEquals("1", "1bc45", StringUtil.replace("12345", "23", "bc"));
        assertEquals("2", "1234ef", StringUtil.replace("12345", "5", "ef"));
        assertEquals("3", "ab2345", StringUtil.replace("12345", "1", "ab"));
        assertEquals("4", "a234a", StringUtil.replace("12341", "1", "a"));
        assertEquals("5", "ab234abab234ab", StringUtil.replace("1234112341", "1", "ab"));

    long newValue = random.nextInt(MAX_ADDEND);
    for (int i = 0; i < ITERATIONS; i++) {
      long before = map.get(key);
      assertFalse(map.replace(key, before + 1, newValue + 1));
      assertFalse(map.replace(key, before - 1, newValue - 1));
      assertTrue(map.replace(key, before, newValue));
      long after = map.get(key);
      assertEquals(newValue, after);
      newValue += newValue;
    }