+ " It is derived from the main artifact.");
    }

    public String getBaseVersion() {
        return parent.getBaseVersion();
    }

    public void setBaseVersion(String baseVersion) {
        throw new UnsupportedOperationException("Cannot change the version information for an attached artifact."
                + " It is derived from the main artifact.");
    }

#### Fix it with `secrets.compare_digest()`

But in our code we are actually using `secrets.compare_digest()`.

In short, it will take the same time to compare `stanleyjobsox` to `stanleyjobson` than it takes to compare `johndoe` to `stanleyjobson`. And the same for the password.

That way, using `secrets.compare_digest()` in your application code, it will be safe against this whole range of security attacks.

   * As such, this field must be cleared before every map mutation.
   *
   * Note about volatile: volatile doesn't make it safe to read from a mutable graph in one thread
   * while writing to it in another. All it does is help with _reading_ from multiple threads
   * concurrently. For more information, see AbstractNetworkTest.concurrentIteration.
   */
  @CheckForNull private transient volatile Entry<K, V> cacheEntry;

    val localTypes: List<ConeKotlinType> = if (isLocal(session)) listOf(this) else {
        typeArguments.mapNotNull {
            if (it is ConeKotlinTypeProjection && it.type.isLocal(session)) {
                it.type
            } else null
        }
    }
    val unavailableLocalTypes = localTypes.filterNot { it.isLocalButAvailableAtPosition(session, useSitePosition) }

    ```Python hl_lines="8-11"
    {!> ../../../docs_src/dependencies/tutorial001.py!}
    ```

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

In this case, this dependency expects:

//
// Otherwise, the [Scanner] advances the input. If the token is not nil,
// the [Scanner] returns it to the user. If the token is nil, the
// Scanner reads more data and continues scanning; if there is no more
// data--if atEOF was true--the [Scanner] returns. If the data does not
// yet hold a complete token, for instance if it has no newline while
// scanning lines, a [SplitFunc] can return (0, nil, nil) to signal the

            .filter { "UNKNOWN" != it.key }
            .filter { model.subprojects.getSubprojectByName(it.key) != null }
            .map { SubprojectTestClassTime(model.subprojects.getSubprojectByName(it.key)!!, it.value.filter { it.testClassAndSourceSet.sourceSet != "test" }) }
            .sortedBy { -it.totalTime }
            .filter { onlyNativeSubprojectsForIntelMacs(testCoverage, it.subProject.name) }

        list.add("ccc");

        final IndexedIterator<String> it = new IndexedIterator<String>(list.iterator());

        assertThat(it.hasNext(), is(true));

        final Indexed<String> indexed1 = it.next();
        assertThat(indexed1.getIndex(), is(0));
        assertThat(indexed1.getElement(), is("aaa"));

        final Indexed<String> indexed2 = it.next();
        assertThat(indexed2.getIndex(), is(1));

    Swagger UI will handle it behind the scenes for you, but it needs this "redirect" helper.

### Create a *path operation* to test it

Now, to be able to test that everything works, create a *path operation*:

```Python hl_lines="36-38"
{!../../../docs_src/custom_docs_ui/tutorial001.py!}
```

### Test it

    ```

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`.