package once

// Singleton contains a pointer to T that must be set once.
// Until the value is set all Get() calls will block.
type Singleton[T any] struct {
	v   *T
	set chan struct{}
}

// NewSingleton creates a new unset singleton.
func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v

	if err != nil {
		t.Fatal(err)
	}

	// Create volume to use in conjunction with other StorageAPI's file API(s)
	err = fs.MakeVol(context.Background(), "voldir")
	if err != nil {
		t.Fatal(err)
	}

	err = fs.AppendFile(context.Background(), "voldir", "/file", []byte("hello"))
	if err != nil {
		t.Fatal(err)
	}

	// Try to create a file that includes a file in its path components.

            UpgradeContext context = createMockContext();

            // Create a temporary directory with a POM file for the test
            Path tempDir = Files.createTempDirectory("apply-test");
            try {
                Path pomFile = tempDir.resolve("pom.xml");
                String pomContent = PomBuilder.create()
                        .groupId("test")
                        .artifactId("test")

        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

  @CollectionFeature.Require(value = SUPPORTS_ITERATOR_REMOVE, absent = KNOWN_ORDER)
  public void testRemovingIteratorUnknownOrder() {

    /**
     * The underlying UUID representing this handle GUID
     */
    private final UUID guid;

    /**
     * Create a new random handle GUID
     */
    public HandleGuid() {
        this.guid = UUID.randomUUID();
    }

    /**
     * Create a handle GUID from existing bytes
     * @param bytes the 16-byte GUID data in little-endian format (SMB wire format)
     */

# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

    RowSortedTable<String, Integer, Character> original = TreeBasedTable.create();
    return unmodifiableRowSortedTable(original);
  }

  @Override
  protected SortedMap<String, Map<Integer, Character>> makePopulatedMap() {
    RowSortedTable<String, Integer, Character> table = TreeBasedTable.create();
    table.put("foo", 1, 'a');
    table.put("bar", 1, 'b');
    table.put("foo", 3, 'c');

  }

  @Override
  Table<Character, String, Integer> makeTable() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    return unmodifiableTable(table);
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    Table<Character, String, Integer> table = HashBasedTable.create();
    table.put('a', "one", 1);
    table.put('a', "two", 2);
    table.put('a', "three", 3);
    table.put('b', "four", 4);

    //
    // 2) Validate local repository directory is accessible.
    //
    // 3) Create RepositorySystemSession.
    //
    // 4) Create MavenSession.
    //
    // 5) Execute AbstractLifecycleParticipant.afterSessionStart(session)
    //
    // 6) Get reactor projects looking for general POM errors
    //
    // 7) Create ProjectDependencyGraph using trimming which takes into account --projects and reactor mode.

---
name: Questions
about: See discuss.codelibs.org
title: 'DO NOT CREATE ME'
labels: ''
assignees: ''

---