You use `which` in Linux and macOS and `Get-Command` in Windows PowerShell.

The way that command works is that it will go and check in the `PATH` environment variable, going through **each path in order**, looking for the program called `python`. Once it finds it, it will **show you the path** to that program.

** Testing mojos

  This can be a problem if the tests are more than simple unit tests;
  that is, if they require configuration of a server process, and
  subsequent testing in-container.

  Since we're only going to concern ourselves with states where localhost is
  still active, we only need to worry about this case when the server container
  is <<not>> installed on localhost. This allows the popular pattern of starting

 */
@GwtCompatible
@NullMarked
public class UnmodifiableCollectionTests {

  public static void assertMapEntryIsUnmodifiable(Entry<?, ?> entry) {
    try {
      // fine because the call is going to fail without modifying the entry
      @SuppressWarnings("unchecked")
      Entry<?, @Nullable Object> nullableValueEntry = (Entry<?, @Nullable Object>) entry;
      nullableValueEntry.setValue(null);

The `security_scopes` object (of class `SecurityScopes`) also provides a `scope_str` attribute with a single string, containing those scopes separated by spaces (we are going to use it).

We create an `HTTPException` that we can reuse (`raise`) later at several points.

	SkipRebalancing bool

	SrcPoolIdx int // set by PutObject/CompleteMultipart operations due to rebalance; used to prevent rebalance src, dst pools to be the same

	DataMovement bool // indicates an going decommisionning or rebalacing

	PrefixEnabledFn func(prefix string) bool // function which returns true if versioning is enabled on prefix

	// IndexCB will return any index created but the compression.

        .Builder()
        .webSocketUpgrade(serverListener)
        .build(),
    )
    val webSocket: WebSocket = newWebSocket()
    clientListener.assertOpen()

    // Send messages until the client's outgoing buffer overflows!
    val message: ByteString = ByteString.of(*ByteArray(1024 * 1024))
    var messageCount: Long = 0
    while (true) {
      val success = webSocket.send(message)
      if (!success) break

   *          |          . PERIOD.
   *          |          .       .
   *        0 +----------+-------+--------------→ storedPermits
   *          0 thresholdPermits maxPermits
   * </pre>
   *
   * Before going into the details of this particular function, let's keep in mind the basics:
   *
   * <ol>
   *   <li>The state of the RateLimiter (storedPermits) is a vertical line in this figure.

Having `str | None` will allow your editor to give you better support and detect errors.

///

## Additional validation { #additional-validation }

We are going to enforce that even though `q` is optional, whenever it is provided, **its length doesn't exceed 50 characters**.

### Import `Query` and `Annotated` { #import-query-and-annotated }

To achieve that, first import:

This code is something you can actually use in your application, save the password hashes in your database, etc.

We are going to start from where we left in the previous chapter and increment it.

## About JWT { #about-jwt }

JWT means "JSON Web Tokens".

  // it doesn't escape this class
  @SuppressWarnings("Immutable")
  private final long[] array;

  /*
   * TODO(kevinb): evaluate the trade-offs of going bimorphic to save these two fields from most
   * instances. Note that the instances that would get smaller are the right set to care about
   * optimizing, because the rest have the option of calling `trimmed`.
   */