OsOpen = os.Open
	// OsOpenFile allows overriding default function.
	OsOpenFile = os.OpenFile
)

// ReadFileWithFileInfo reads the named file and returns the contents.
// A successful call returns err == nil, not err == EOF.
// Because ReadFile reads the whole file, it does not treat an EOF from Read
// as an error to be reported.
func ReadFileWithFileInfo(name string) ([]byte, fs.FileInfo, error) {

const maxInt = int(^uint(0) >> 1)

// Bytes returns a slice of length b.Len() holding the unread portion of the buffer.
// The slice is valid for use only until the next buffer modification (that is,
// only until the next call to a method like [Buffer.Read], [Buffer.Write], [Buffer.Reset], or [Buffer.Truncate]).
// The slice aliases the buffer content at least until the next buffer modification,

    boolean collide = false; // True if last slot nonempty
    for (; ; ) {
      Cell[] as;
      Cell a;
      int n;
      long v;
      if ((as = cells) != null && (n = as.length) > 0) {
        if ((a = as[(n - 1) & h]) == null) {
          if (busy == 0) { // Try to attach new Cell
            Cell r = new Cell(x); // Optimistically create
            if (busy == 0 && casBusy()) {

    /**
     * It is implicitly assumed that all the services are NEW and that they will all remain NEW
     * until all the Listeners are installed and {@link #markReady()} is called. It is our caller's
     * responsibility to only call {@link #markReady()} if all services were new at the time this
     * method was called and when all the listeners were installed.
     */

    @Override
    public final T call() {
      try {
        return realCall();
      } catch (Throwable t) {
        threadUnexpectedException(t);
        return null;
      }
    }
  }

  public abstract class CheckedInterruptedCallable<T> implements Callable<T> {
    protected abstract T realCall() throws Throwable;

    @Override
    public final T call() {
      try {

# Debugging

You can connect the debugger in your editor, for example with Visual Studio Code or PyCharm.

## Call `uvicorn`

In your FastAPI application, import and run `uvicorn` directly:

```Python hl_lines="1  15"
{!../../docs_src/debugging/tutorial001.py!}
```

### About `__name__ == "__main__"`

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

    ListeningScheduledExecutorService executor = TestingExecutors.noOpScheduledExecutor();
    taskDone = false;
    Callable<Boolean> task =
        new Callable<Boolean>() {
          @Override
          public Boolean call() {
            taskDone = true;
            return taskDone;
          }
        };
    List<Future<Boolean>> futureList = executor.invokeAll(ImmutableList.of(task), 10, MILLISECONDS);

        .connectionSpecs(listOf(spec))
        .eventListenerFactory(
          clientTestRule.wrap(
            object : EventListener() {
              override fun connectionAcquired(
                call: Call,
                connection: Connection,
              ) {
                val sslSocket = connection.socket() as SSLSocket

                sessionIds.add(sslSocket.session.id.toByteString().hex())

    /**
     * It is implicitly assumed that all the services are NEW and that they will all remain NEW
     * until all the Listeners are installed and {@link #markReady()} is called. It is our caller's
     * responsibility to only call {@link #markReady()} if all services were new at the time this
     * method was called and when all the listeners were installed.
     */

   * given executor at the first call to {@code addListener}. The task must be started by the
   * executor promptly, or else the returned {@code ListenableFuture} may fail to work. The task's
   * execution consists of blocking until the input future is {@linkplain Future#isDone() done}, so
   * each call to this method may claim and hold a thread for an arbitrary length of time. Use of