lockerEpSet := set.NewStringSet()
		for j := range setDriveCount {
			wg.Add(1)
			go func(i int, endpoint Endpoint) {
				defer wg.Done()

				lk.Lock()
				// Only add lockers only one per endpoint and per erasure set.
				if locker, ok := erasureLockers[endpoint.Host]; ok && !lockerEpSet.Contains(endpoint.Host) {
					lockerEpSet.Add(endpoint.Host)
					s.erasureLockers[i] = append(s.erasureLockers[i], locker)
				}

     *
     * @param elements the {@code Iterable} to add to the {@code ImmutableList}
     * @return this {@code Builder} object
     * @throws NullPointerException if {@code elements} is null or contains a null element
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E... elements) {
      checkElementsNotNull(elements);
      add(elements, elements.length);
      return this;
    }

Notice how the callback URL used contains the URL received as a query parameter in `callback_url` (`https://www.external.org/events`) and also the invoice `id` from inside of the JSON body (`2expen51ve`).

///

### Add the callback router { #add-the-callback-router }

At this point you have the *callback path operation(s)* needed (the one(s) that the *external developer*  should implement in the *external API*) in the callback router you created above.

	if r.columnNames == nil {
		r.columnNames = make([]string, len(csvRecord))
		for i := range csvRecord {
			r.columnNames[i] = fmt.Sprintf("_%v", i+1)
		}
	}

	// If no index map, add that.
	if r.nameIndexMap == nil {
		r.nameIndexMap = make(map[string]int64)
		for i := range r.columnNames {
			r.nameIndexMap[r.columnNames[i]] = int64(i)
		}
	}
	dstRec, ok := dst.(*Record)
	if !ok {

            "${prefix}TestImplementation"(project(":internal-integ-testing"))
            "${prefix}TestFullDistributionRuntimeClasspath"(project(":distributions-full"))
            // Add the agent JAR to the test runtime classpath so the InProcessGradleExecuter can find the module and spawn daemons.
            // This doesn't apply the agent to the test process.

    /**
     * Add the specified range to this builder. Adjacent ranges are permitted and will be merged,
     * but overlapping ranges will cause an exception when {@link #build()} is called.
     *
     * @throws IllegalArgumentException if {@code range} is empty
     */
    @CanIgnoreReturnValue
    public Builder<C> add(Range<C> range) {

    for (String entry : Splitter.on(PATH_SEPARATOR.value()).split(JAVA_CLASS_PATH.value())) {
      try {
        try {
          urls.add(new File(entry).toURI().toURL());
        } catch (SecurityException e) { // File.toURI checks to see if the file is a directory
          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {

        for (MojoExecution execution : mojoExecutions) {
            MojoDescriptor mojoDescriptor = fillMojoDescriptor(session, project, execution);
            descriptors.add(mojoDescriptor);
        }

        return descriptors;
    }

    private MojoDescriptor fillMojoDescriptor(MavenSession session, MavenProject project, MojoExecution execution)

//	LADDW rreg ',' sreg ',' rreg
//	{
//		outcode(int($1), &$2, int($4), &$6);
//	}
	ADD	R5, R9, R10	// 01255020
	ADDU	R13, R14, R19	// 01cd9821
	ADDV	R5, R9, R10	// 0125502c
	ADDVU	R13, R14, R19	// 01cd982d

//	LADDW imm ',' sreg ',' rreg
//	{
//		outcode(int($1), &$2, int($4), &$6);
//	}
	ADD	$15176, R14, R9	// 21c93b48
	ADD	$-9, R5, R8	// 20a8fff7
	ADDU	$10, R9, R9	// 2529000a
	ADDV	$15176, R14, R9	// 61c93b48

      iteratorElements.add(element);
    }
    assertEqualIgnoringOrder(asList(createSamplesArray()), iteratorElements);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testIterationOrdering() {
    List<E> iteratorElements = new ArrayList<>();
    for (E element : collection) { // uses iterator()
      iteratorElements.add(element);
    }