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

     *
     * @return an {@link Optional} containing the list of goals, or empty if not specified
     */
    @Nonnull
    Optional<List<String>> goals();

    /**
     * Returns the target POM model version for upgrades.
     * Supported values include "4.0.0" and "4.1.0".
     *
     * @return an {@link Optional} containing the model version, or empty if not specified
     */
    @Nonnull
    Optional<String> modelVersion();

     *
     * @param pattern
     *            The date pattern. Must not be {@literal null} or an empty string.
     * @param propertyNames
     *            An array of property names. Each element must not be {@literal null} or an empty string.
     * @return A {@link CopyOptions} with a date converter applied.
     * @see CopyOptions#dateConverter(String, CharSequence...)

        };

        assertEquals("Empty minKey should be empty string", "", emptyKeysAnnotation.minKey());
        assertEquals("Empty maxKey should be empty string", "", emptyKeysAnnotation.maxKey());
        assertTrue("Empty minKey should match StringUtil.EMPTY", StringUtil.EMPTY.equals(emptyKeysAnnotation.minKey()));
        assertTrue("Empty maxKey should match StringUtil.EMPTY", StringUtil.EMPTY.equals(emptyKeysAnnotation.maxKey()));
    }

     * Processes collection definitions and tracks the element hierarchy.
     *
     * @param uri the namespace URI, or empty string if none
     * @param localName the local name without prefix, or empty string if namespace processing is not performed
     * @param qName the qualified name with prefix, or empty string if qualified names are not available
     * @param attributes the attributes attached to the element

    }

    /**
     * Returns the bundle. Returns <code>null</code> if not found.
     *
     * @param name the resource bundle name (must not be {@literal null} or empty)
     * @param locale the locale
     * @param classLoader the class loader (must not be {@literal null} or empty)
     * @return {@link ResourceBundle}
     * @see ResourceBundle#getBundle(String, Locale, ClassLoader)
     */

     * Even if empty string, treated as empty plainly. So "IF pmb != null" is false if empty.
     * @param hostname The parameter value of hostname. (NotNull)
     */
    public void setHostname(String hostname) {
        registerVariable("hostname", hostname);
    }

    /**
     * Set the value of clustername, used in parameter comment. <br>

  }

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

    assertThat(Booleans.concat()).isEqualTo(EMPTY);
    assertThat(Booleans.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Booleans.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Booleans.concat(ARRAY_FALSE)).isEqualTo(ARRAY_FALSE);
    assertThat(Booleans.concat(ARRAY_FALSE)).isNotSameInstanceAs(ARRAY_FALSE);
    assertThat(Booleans.concat(EMPTY, ARRAY_FALSE, EMPTY)).isEqualTo(ARRAY_FALSE);