assertNotNull(emptyUnicodeStringTrue.buffer, "Buffer should not be null for empty string with zterm");
        assertEquals(1, emptyUnicodeStringTrue.buffer.length, "Buffer length should be 1 for empty string with zterm");
        assertEquals(0, emptyUnicodeStringTrue.buffer[0], "Buffer should contain only zero for empty string with zterm");

        // Test with an empty string and zterm = false

    /**
     * Asserts that the argument is neither <code>null</code> nor an empty string.
     *
     * @param argName
     *            The name of the argument that must not be {@code null} or an empty string.
     * @param argValue
     *            The value of the argument.
     * @throws EmptyArgumentException
     *             If the argument is <code>null</code> or an empty string.
     */

        assertEquals(0, blob.get().length, "Internal array should be empty");
        assertEquals(0, blob.length(), "length() should be 0 for empty");
        assertEquals("", blob.toString(), "toString() of empty should be empty string");
        assertTrue(blob.equals(blob), "Object should be equal to itself");

  public void testConcat() {
    assertThat(Bytes.concat()).isEqualTo(EMPTY);
    assertThat(Bytes.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Bytes.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Bytes.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Bytes.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Bytes.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Bytes.concat(ARRAY1, ARRAY1, ARRAY1))

    }

    /**
     * Returns the resource from the context class loader.
     *
     * @param path
     *            The resource path. Must not be {@literal null} or empty string.
     * @return The resource {@link URL}
     * @see #getResource(String, String)
     */
    public static URL getResource(final String path) {
        assertArgumentNotEmpty("path", path);

        System.clearProperty("123");
        System.clearProperty("test_var");
    }

    public void test_resolve_edgeCases() {
        // Test empty property replacement
        System.setProperty("empty", "");
        String value = "${empty}";
        assertEquals("", ResourceUtil.resolve(value));

        // Test property with just spaces
        System.setProperty("spaces", "   ");

    expectContents();
  }

  // retainAll(null)

  /*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

    }

    public void test_empty() {
        // Test empty user bean creation
        FessUserBean emptyBean = FessUserBean.empty();
        assertNotNull(emptyBean);

        // Test getUserId returns EMPTY_USER_ID
        assertEquals(Constants.EMPTY_USER_ID, emptyBean.getUserId());

        // Test hasRoles always returns true for empty user
        assertTrue(emptyBean.hasRoles(new String[] { "admin" }));

  public void testConcat() {
    assertThat(Chars.concat()).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Chars.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1, ARRAY1, ARRAY1))

            }

            @Override
            protected String getClientIp() {
                return StringUtil.EMPTY;
            }
        };
    }

    public void test_login() {
        activityHelper.useEcsFormat = false;
        activityHelper.login(OptionalThing.empty());
        assertEquals("action:LOGIN\tuser:-\tpermissions:-", localLogMsg.get());