{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[13] *}

Let's focus on the parameters declared:

* Even though this function is a dependency ("dependable") itself, it also declares another dependency (it "depends" on something else).
    * It depends on the `query_extractor`, and assigns the value returned by it to the parameter `q`.
* It also declares an optional `last_query` cookie, as a `str`.

            timeZone = UTC
          }
        BROWSER_COMPATIBLE_DATE_FORMATS[i] = format
      }
      position.index = 0
      result = format.parse(this, position)
      if (position.index != 0) {
        // Something was parsed. It's possible the entire string was not consumed but we ignore
        // that. If any of the BROWSER_COMPATIBLE_DATE_FORMAT_STRINGS ended in "'GMT'" we'd have

 *       probably require adding the dep to various ACLs, license files, and Proguard
 *       configurations, and there's always the potential that something will go wrong. It
 *       <i>probably</i> won't, since the deps are needed only in tests (and maybe someday in
 *       testlib), but why bother?

  /*
   * We are comparing Multimaps of the same type, so as long as they have value collections that
   * implement equals() (as with ListMultimap or SetMultimap, as opposed to a QueueMultimap or
   * something), our equality check is value-based.
   */
  @SuppressWarnings("UndefinedEquals")
  public void testRetainAllPropagatesToMultimap() {
    multimap().entries().retainAll(singleton(mapEntry(k0(), v0())));

  private MinimalIterable(Iterator<E> iterator) {
    this.iterator = iterator;
  }

  @Override
  public Iterator<E> iterator() {
    if (iterator == null) {
      // TODO: throw something else? Do we worry that people's code and tests
      // might be relying on this particular type of exception?
      throw new IllegalStateException();
    }
    try {
      return iterator;
    } finally {

GOIOS_DEV_ID, GOIOS_TEAM_ID and GOIOS_APP_ID. The detect.go program in this directory will
attempt to auto-detect suitable values. Run it as

	go run detect.go

which will output something similar to

	export GOIOS_DEV_ID="iPhone Developer: ******@****.*** (XXXXXXXX)"
	export GOIOS_APP_ID=YYYYYYYY.some.bundle.id
	export GOIOS_TEAM_ID=ZZZZZZZZ

    * An example is `404`, for a "Not Found" response.
    * For generic errors from the client, you can just use `400`.
* `500 - 599` are for server errors. You almost never use them directly. When something goes wrong at some part in your application code, or server, it will automatically return one of these status codes.

/// tip

So, you can use `user_agent` as you normally would in Python code, instead of needing to capitalize the first letters as `User_Agent` or something similar.

If for some reason you need to disable automatic conversion of underscores to hyphens, set the parameter `convert_underscores` of `Header` to `False`:

{* ../../docs_src/header_params/tutorial002_an_py310.py hl[10] *}

   *
   * ```
   * [5] EXPLICIT UTF8String
   * ```
   *
   * @param forceConstructed non-null to set the constructed bit to the specified value, even if the
   *     writing process sets something else. This is used to encode SEQUENCES in values that are
   *     declared to have non-constructed values, like OCTET STRING values.
   */
  @Suppress("UNCHECKED_CAST") // read() produces a single element of the expected type.

 *   <li><b>Convenience methods:</b> These are implementations of common operations that are
 *       typically implemented by opening a stream using one of the methods in the first category,
 *       doing something and finally closing the stream or channel that was opened.
 * </ul>
 *
 * @since 14.0
 * @author Colin Decker
 */
@J2ktIncompatible
@GwtIncompatible
public abstract class ByteSink {