assertEquals(expected, CharSource.concat(ImmutableList.of(c1, c2, c3).iterator()).read());
    assertFalse(CharSource.concat(c1, c2, c3).isEmpty());

    CharSource emptyConcat = CharSource.concat(CharSource.empty(), CharSource.empty());
    assertTrue(emptyConcat.isEmpty());
  }

  public void testConcat_infiniteIterable() throws IOException {
    CharSource source = CharSource.wrap("abcd");

        try (Stream<String> lines = Files.lines(configFile, Charset.defaultCharset())) {
            List<String> args =
                    lines.filter(arg -> !arg.isEmpty() && !arg.startsWith("#")).toList();
            O options = parseArgs("maven.config", args);
            if (options.goals().isPresent()) {
                // This file can only contain options, not args (goals or phases)

        } else {
            fileConfigList = Collections.emptyList();
        }

        if (webConfigList.isEmpty() && fileConfigList.isEmpty()) {
            // nothing
            if (logger.isInfoEnabled()) {
                logger.info("No crawling target urls.");
            }
            return;
        }

        final ListResultBean<DataConfig> list = dataConfigBhv.selectList(cb -> {
            cb.query().setName_Equal(name);
            cb.query().addOrderBy_SortOrder_Asc();
        });
        if (list.isEmpty()) {
            return OptionalEntity.empty();
        }
        return OptionalEntity.of(list.get(0));
    }

    public void store(final DataConfig dataConfig) {

        if (rev != null || timestamp != null) {
            msg += " (";
            msg += (rev != null ? rev : "");
            if (timestamp != null && !timestamp.isEmpty()) {
                String ts = formatTimestamp(Long.parseLong(timestamp));
                msg += (rev != null ? "; " : "") + ts;
            }
            msg += ")";
        }
        return msg;
    }

            if (methodLinkMetaData.name.equals(method)) {
                candidates.add(methodLinkMetaData);
            }
        }
        if (candidates.isEmpty()) {
            String message = String.format("No method '%s' found for class '%s'.\nFound the following methods:", method, className);
            for (MethodLinkMetaData methodLinkMetaData : methods.values()) {

    assertThat(Doubles.join(",", EMPTY)).isEmpty();
    assertThat(Doubles.join(",", ARRAY1)).isEqualTo("1.0");
    assertThat(Doubles.join(",", (double) 1, (double) 2)).isEqualTo("1.0,2.0");
    assertThat(Doubles.join("", (double) 1, (double) 2, (double) 3)).isEqualTo("1.02.03.0");
  }

  public void testJoinNonTrivialDoubles() {
    assertThat(Doubles.join(",", EMPTY)).isEmpty();

  }

  public void testIsEmpty() {
    Iterable<String> emptyList = emptyList();
    assertTrue(Iterables.isEmpty(emptyList));

    Iterable<String> singletonList = singletonList("foo");
    assertFalse(Iterables.isEmpty(singletonList));
  }

  public void testSkip_simple() {
    Collection<String> set = ImmutableSet.of("a", "b", "c", "d", "e");

		newPolicySet = existingPolicySet.Difference(policiesToUpdate)
	}
	// We return an error if the requested policy update will have no effect.
	if policiesToUpdate.IsEmpty() {
		err = errNoPolicyToAttachOrDetach
		return
	}

	newPolicies := newPolicySet.ToSlice()
	newPolicyMapping.Policies = strings.Join(newPolicies, ",")
	newPolicyMapping.UpdatedAt = UTCNow()

    assertEquals(0, service.startUpCalled);
    assertEquals(0, service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());
    assertThat(service.transitionStates).isEmpty();
  }

  public void testStop_afterStart() {
    TestService service = new TestService();
    service.startAsync().awaitRunning();
    assertEquals(1, service.startUpCalled);