// initialized when the provided function returns nil.

// Init represents the structure.
type Init struct {
	done uint32
	m    sync.Mutex
}

// Do is similar to sync.Once.Do - makes one successful
// call to the function. ie, it invokes the function
// if it is not successful yet.
func (l *Init) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.do(f)
	}
	return nil
}

          int x = n / i;
          if (x * i == n) return factor(x) + " × " + i;
        }
        return Integer.toString(n);
      }
    };

    thread.start();
  }

  /**
   * This request body makes it possible for another thread to stream data to the uploading request.
   * This is potentially useful for posting live event streams like video capture. Callers should
   * write to {@code sink()} and close it to complete the post.

		// not be required but makes reproduction much easier.
		nsLk.lockMapMutex.Lock()

		// lk3 blocks.
		lk3ch := make(chan bool)
		go func() {
			lk3ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
		}()

		// lk4, blocks.
		lk4ch := make(chan bool)
		go func() {
			lk4ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)

# "/path/bar". This script uses "gsutil rsync" instead, which acts on directory
# contents. About arguments to gsutil:
# "gsutil -m rsync" runs in parallel.
# "gsutil rsync -r" is recursive and makes directories work.
# "gsutil rsync -d" is "sync and delete files from destination if not present in source"

DOWNLOADS="$(mktemp -d)"
mkdir -p "$DOWNLOADS"
gsutil -m rsync -r "$TFCI_ARTIFACT_STAGING_GCS_URI" "$DOWNLOADS"

```
.
├── app                  # "app" is a Python package
│   ├── __init__.py      # this file makes "app" a "Python package"
│   ├── main.py          # "main" module, e.g. import app.main
│   ├── dependencies.py  # "dependencies" module, e.g. import app.dependencies
│   └── routers          # "routers" is a "Python subpackage"
│   │   ├── __init__.py  # makes "routers" a "Python subpackage"

   *   <li>Otherwise, return an instance of {@link ClusterException} that wraps the first exception
   *       in the {@code exceptions} collection.
   * </ul>
   *
   * <p>Though this method takes any {@link Collection}, it often makes most sense to pass a {@link
   * java.util.List} or some other collection that preserves the order in which the exceptions got
   * added.
   *
   * @throws NullPointerException if {@code exceptions} is null

      runTest();
    } finally {
      tearDown();
    }
  }

  @Override
  protected void tearDown() {
    tearDownStack.runTearDown();
  }

  /** Builds a {@link TearDownStack} that makes sure it's clear by the end of this test. */
  private TearDownStack buildTearDownStack() {
    final TearDownStack result = new TearDownStack();
    tearDownStack.addTearDown(
        new TearDown() {

 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this

 *       even on an {@code ImmutableMap<K, @NonNull String>}.
 * </ul>
 *
 * <p>Consumers of this annotation include:
 *
 * <ul>
 *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
 *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this

1. Creating a PR and observing the presubmit test results
2. Running the CI scripts locally, as explained below
3. **Google employees only**: Google employees can use an internal-only tool
called "MLCI" that makes testing more convenient: it can execute any full CI job
against a pending change. Search for "MLCI" internally to find it.

You may invoke a CI script of your choice by following these instructions:

```bash