func (v *myProtoValue) keyAsStruct(key string) *myProtoValue {
	if v == nil || v.GetStructValue() == nil {
		return asMyProtoValue(&structpb.Struct{Fields: make(map[string]*structpb.Value)})
	}

	return &myProtoValue{v.GetStructValue().Fields[key]}
}

// asMyProtoValue wraps a protobuf Struct so we may use it with keyAsStruct and keyAsString
func asMyProtoValue(s *structpb.Struct) *myProtoValue {

	return k[:], err
}

// ParseSSECustomerRequest parses the SSE-C header fields of the provided request.
// It returns the client provided key on success.
func ParseSSECustomerRequest(r *http.Request) (key []byte, err error) {
	return ParseSSECustomerHeader(r.Header)
}

// ParseSSECustomerHeader parses the SSE-C header fields and returns
// the client provided key on success.

///

## Type Hints với Metadata Annotations

Python cũng có một tính năng cho phép đặt **metadata bổ sung** trong những gợi ý kiểu dữ liệu này bằng cách sử dụng `Annotated`.

    static final int IN = 0x0001;
    static final int A = 0x0001;
    static final int NS = 0x0002;
    static final int NULL = 0x000a;

    static final int HEADER_LENGTH = 12;

    // header field offsets
    static final int OPCODE_OFFSET = 2;
    static final int QUESTION_OFFSET = 4;
    static final int ANSWER_OFFSET = 6;
    static final int AUTHORITY_OFFSET = 8;
    static final int ADDITIONAL_OFFSET = 10;

    static final int A         = 0x0001;
    static final int NS        = 0x0002;
    static final int NULL      = 0x000a;

    static final int HEADER_LENGTH = 12;

    // header field offsets
    static final int OPCODE_OFFSET = 2;
    static final int QUESTION_OFFSET = 4;
    static final int ANSWER_OFFSET = 6;
    static final int AUTHORITY_OFFSET = 8;
    static final int ADDITIONAL_OFFSET = 10;

			return err
		}
	} else {
		// Evaluate the (only) argument
		val, err = e.SFunc.ArgsList[0].evalNode(r, tableAlias)
		if err != nil {
			return err
		}
	}

	if val.IsNull() {
		// E.g. the column or field does not exist in the
		// record - in all such cases the aggregation is not
		// updated.
		return nil
	}

	argVal := val
	if funcName != aggFnCount {
		// All aggregation functions, except COUNT require a

            final String fieldName = jsonParser.getCurrentName();
            if (fieldName != null) {
                jsonParser.nextToken(); // Move to the value of the current field

                if (jsonParser.getCurrentToken() == JsonToken.START_ARRAY) {
                    nestedMap.put(fieldName, parseArray(jsonParser));

    private BelowAll() {
      /*
       * No code ever sees this bogus value for `endpoint`: This class overrides both methods that
       * use the `endpoint` field, compareTo() and endpoint(). Additionally, the main implementation
       * of Cut.compareTo checks for belowAll before reading accessing `endpoint` on another Cut
       * instance.
       */
      super("");
    }

    assertThat(timer.elapsed(MILLISECONDS)).isAtLeast(10L);
    // wait for interrupted status and clear it
    while (!Thread.interrupted()) {
      Thread.yield();
    }
  }

  private static class Producer implements Callable<@Nullable Void> {
    final BlockingQueue<Object> q;
    final int elements;
    final CountDownLatch beganProducing = new CountDownLatch(1);

   * implementation. Experimentally determined.
   */
  private static final int MAX_HASH_BUCKET_LENGTH = 9;

  // See CompactHashMap for a detailed description of how the following fields work. That
  // description talks about `keys`, `values`, and `entries`; here the `keys` and `values` arrays
  // are replaced by a single `elements` array but everything else works similarly.

  /**