assertEquals("gmail.com", hp.getHost());
    assertTrue(hp.hasPort());
    assertEquals(81, hp.getPort());

    assertThrows(IllegalArgumentException.class, () -> HostAndPort.fromParts("gmail.com:80", 81));

    assertThrows(IllegalArgumentException.class, () -> HostAndPort.fromParts("gmail.com", -1));
  }

  public void testFromHost() {
    HostAndPort hp = HostAndPort.fromHost("gmail.com");

    Map<String, Integer> filtered = Maps.filterKeys(unfiltered, NOT_LENGTH_3);
    filtered.put("a", 1);
    filtered.put("b", 2);
    assertEquals(ImmutableMap.of("a", 1, "b", 2), filtered);

    assertThrows(IllegalArgumentException.class, () -> filtered.put("yyy", 3));
  }

  public void testFilteredKeysIllegalPutAll() {
    Map<String, Integer> unfiltered = createUnfiltered();

   *
   * @param expression a boolean expression
   * @throws IllegalArgumentException if {@code expression} is false
   */
  public static void checkArgument(boolean expression) {
    if (!expression) {
      throw new IllegalArgumentException();
    }
  }

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.

     * @param dataStore the data store instance to register, must not be null
     * @throws IllegalArgumentException if either name or dataStore is null
     */
    public void add(final String name, final DataStore dataStore) {
        if (name == null || dataStore == null) {
            throw new IllegalArgumentException("name or dataStore is null.");
        }
        if (logger.isDebugEnabled()) {

    public void fetchFirst(int fetchSize) {
        _fetchScopeEffective = true;
        if (fetchSize < 0) {
            String msg = "Argument[fetchSize] should be plus: " + fetchSize;
            throw new IllegalArgumentException(msg);
        }
        _fetchStartIndex = 0;
        _fetchSize = fetchSize;
        _fetchPageNumber = 1;
        doClearFetchPageClause();
        doFetchFirst();
    }

    public static HandleType fromValue(int value) {
        for (HandleType type : values()) {
            if (type.value == value) {
                return type;
            }
        }
        throw new IllegalArgumentException("Unknown handle type value: " + value);
    }

    @DisplayName("valueOf with unknown or differently-cased names throws IllegalArgumentException")
    void valueOfRejectsUnknownOrCaseMismatch(String badName) {
        IllegalArgumentException ex = assertThrows(IllegalArgumentException.class, () -> RequestParam.valueOf(badName));
        assertTrue(ex.getMessage().contains(badName), "Exception message should mention the bad name");
    }

    Resources.copy(resource, out);
    assertEquals(I18N, out.toString("UTF-8"));
  }

  public void testGetResource_notFound() {
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class, () -> Resources.getResource("no such resource"));
    assertThat(e).hasMessageThat().isEqualTo("resource no such resource not found.");
  }

   * Entries appear in the result {@code ImmutableBiMap} in encounter order.
   *
   * <p>If the mapped keys or values contain duplicates (according to {@link
   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *

    for (BigInteger x : NEGATIVE_BIGINTEGER_CANDIDATES) {
      assertThrows(IllegalArgumentException.class, () -> BigIntegerMath.ceilingPowerOfTwo(x));
    }
  }

  public void testFloorPowerOfTwoNegative() {
    for (BigInteger x : NEGATIVE_BIGINTEGER_CANDIDATES) {
      assertThrows(IllegalArgumentException.class, () -> BigIntegerMath.floorPowerOfTwo(x));
    }
  }

  public void testCeilingPowerOfTwoZero() {