}
			f.Close()
		}

		bs, err := os.ReadFile(goldenFile)
		if err != nil {
			t.Fatalf("opening golden.txt for package %q: %v", fi.Name(), err)
		}
		wanted := strings.Split(string(bs), "\n")
		slices.Sort(wanted)
		for _, feature := range wanted {
			if feature == "" {
				continue
			}
			_, ok := w.features[feature]
			if !ok {
				t.Errorf("package %s: missing feature %q", fi.Name(), feature)
			}

			zb0002, err = dc.ReadArrayHeader()
			if err != nil {
				err = msgp.WrapError(err, "ObjSizes")
				return
			}
			if zb0002 != uint32(dataUsageBucketLen) {
				err = msgp.ArrayError{Wanted: uint32(dataUsageBucketLen), Got: zb0002}
				return
			}
			for za0001 := range z.ObjSizes {
				z.ObjSizes[za0001], err = dc.ReadUint64()
				if err != nil {

				var zb0006 uint32
				zb0006, err = dc.ReadArrayHeader()
				if err != nil {
					err = msgp.WrapError(err, zb0001, "Bins")
					return
				}
				if zb0006 != uint32(24) {
					err = msgp.ArrayError{Wanted: uint32(24), Got: zb0006}
					return
				}
				for zb0003 := range zb0002.Bins {
					err = zb0002.Bins[zb0003].DecodeMsg(dc)
					if err != nil {
						err = msgp.WrapError(err, zb0001, "Bins", zb0003)
						return

				t.Errorf("parseHexUint(%q) = %v, %v; want error %q", tt.in, got, err, tt.wantErr)
			}
		} else {
			if err != nil || got != tt.want {
				t.Errorf("parseHexUint(%q) = %v, %v; want %v", tt.in, got, err, tt.want)
			}
		}
	}

	var zb0001 uint32
	zb0001, bts, err = msgp.ReadArrayHeaderBytes(bts)
	if err != nil {
		err = msgp.WrapError(err)
		return o, err
	}
	if zb0001 != 4 {
		err = msgp.ArrayError{Wanted: 4, Got: zb0001}
		return o, err
	}
	bts, err = msgp.ReadExactBytes(bts, (x.VersionID)[:])
	if err != nil {
		err = msgp.WrapError(err, "VersionID")
		return o, err
	}

## Design { #design }

Then I spent some time designing the developer "API" I wanted to have as a user (as a developer using FastAPI).

I tested several ideas in the most popular Python editors: PyCharm, VS Code, Jedi based editors.

     * when we run AbstractFutureTest itself.
     */

    /*
     * We don't test UnsafeAtomicHelper here, since guava-android doesn't provide a way to use it
     * under the JVM. (We could arrange for one if we really wanted, but that will break once the
     * JDK further restricts access to Unsafe.) But we have coverage under an Android emulator,
     * which uses UnsafeAtomicHelper when it runs AbstractFutureTest itself.
     */

## Return Type and Data Filtering { #return-type-and-data-filtering }

Let's continue from the previous example. We wanted to **annotate the function with one type**, but we wanted to be able to return from the function something that actually includes **more data**.

          if (comparator == null) {
            // A sorted spliterator with no comparator is already using natural order.
            // (We could probably find a way to avoid rawtypes here if we wanted.)
            @SuppressWarnings({"unchecked", "rawtypes"})
            Comparator<? super E> naturalOrder =
                (Comparator<? super E>) Comparator.<Comparable>naturalOrder();
            comparator = naturalOrder;

          if (comparator == null) {
            // A sorted spliterator with no comparator is already using natural order.
            // (We could probably find a way to avoid rawtypes here if we wanted.)
            @SuppressWarnings({"unchecked", "rawtypes"})
            Comparator<? super E> naturalOrder =
                (Comparator<? super E>) Comparator.<Comparable>naturalOrder();
            comparator = naturalOrder;