You can customize that function. It takes an `APIRoute` and outputs a string.

For example, here it is using the first tag (you will probably have only one tag) and the *path operation* name (the function name).

You can then pass that custom function to **FastAPI** as the `generate_unique_id_function` parameter:

{* ../../docs_src/generate_clients/tutorial003_py39.py hl[6:7,10] *}

        TestAuthenticationChain chain = new TestAuthenticationChain();
        chain.changePasswordThrowsException = true;

        try {
            chain.changePassword("user", "pass");
            fail("Expected exception to be thrown");
        } catch (RuntimeException e) {
            assertEquals("Change password failed", e.getMessage());
        }

					// PASS
				}
			default:
				logger.Default.Warn(context.Background(), "Model %v don't match %vInterface, should be `%v(*gorm.DB) error`. Please see https://gorm.io/docs/hooks.html", schema, cbName, cbName)
			}
		}
	}

* The variable `items_t` is a `tuple` with 3 items, an `int`, another `int`, and a `str`.
* The variable `items_s` is a `set`, and each of its items is of type `bytes`.

#### Dict { #dict }

To define a `dict`, you pass 2 type parameters, separated by commas.

The first type parameter is for the keys of the `dict`.

The second type parameter is for the values of the `dict`:

//// tab | Python 3.9+

```Python hl_lines="1"

    /**
     * Reserve an opportunistic lock filter on the open
     */
    public static final int FILE_RESERVE_OPFILTER = 0x100000;
    /**
     * Open a reparse point and bypass normal reparse point processing
     */
    public static final int FILE_OPEN_REPARSE_POINT = 0x200000;
    /**
     * Open does not cause an opportunistic lock break for the file
     */

        shift                   # remove old arg
        set -- "$@" "$arg"      # push replacement arg
    done
fi


# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'

# Collect all arguments for the java command:
#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,

			}
		}
	}
}

// Tests validate bucket name.
func TestIsValidBucketName(t *testing.T) {
	testCases := []struct {
		bucketName string
		shouldPass bool
	}{
		// cases which should pass the test.
		// passing in valid bucket names.
		{"lol", true},
		{"1-this-is-valid", true},
		{"1-this-too-is-valid-1", true},
		{"this.works.too.1", true},
		{"1234567", true},
		{"123", true},

// device and related kernels present in that library. This function is not
// supported on embedded on mobile and embedded platforms and will fail if
// called.
//
// Pass "library_filename" to a platform-specific mechanism for dynamically
// loading a library. The rules for determining the exact location of the
// library are platform-specific and are not documented here.
//

   */

  /*
   * These generators also rely on consecutive integer inputs (not necessarily in order, but no
   * holes).
   */

  // SetCreationTester has some tests that pass in duplicates. Dedup them.
  private static <E extends Comparable<? super E>> SortedSet<E> nullCheckedTreeSet(E[] elements) {
    SortedSet<E> set = newTreeSet();
    for (E element : elements) {

    return new FunctionToCacheLoader<>(function);
  }

  /**
   * Returns a cache loader based on an <i>existing</i> supplier instance. Note that there's no need
   * to create a <i>new</i> supplier just to pass it in here; just subclass {@code CacheLoader} and
   * implement {@link #load load} instead.
   *
   * <p>The returned object is serializable if {@code supplier} is serializable.
   *