1. The id_token is an identifier that is hard to guess. For example, a randomly generated string of sufficient length, that the server handling the protected resource can use to lookup the associated authorization information.
2. The id_token self-contains the authorization information in a manner that can be verified. For example, by encoding authorization information along with a signature into the token.

## Singular values in body { #singular-values-in-body }

The same way there is a `Query` and `Path` to define extra data for query and path parameters, **FastAPI** provides an equivalent `Body`.

For example, extending the previous model, you could decide that you want to have another key `importance` in the same body, besides the `item` and `user`.

    private KerberosKey[] keys;

    private static final String SERVER_REALM = "EXAMPLE.COM";
    private static final String SERVER_PRINCIPAL_NAME = "krbtgt/EXAMPLE.COM";
    private static final String USER_PRINCIPAL_NAME = "user@EXAMPLE.COM";
    private static final String USER_REALM = "EXAMPLE.COM";
    private static final int ENCRYPTION_TYPE = 23; // aes128-cts-hmac-sha1-96

      run = true;
    }
  }

  private static class TestCallable implements Callable<String> {
    @Override
    public String call() {
      return "foo";
    }
  }

  /** Simple same thread listening executor service that doesn't handle shutdown. */
  private static class TestListeningExecutorService extends AbstractListeningExecutorService {

    @Override
    public void execute(Runnable runnable) {

      run = true;
    }
  }

  private static class TestCallable implements Callable<String> {
    @Override
    public String call() {
      return "foo";
    }
  }

  /** Simple same thread listening executor service that doesn't handle shutdown. */
  private static class TestListeningExecutorService extends AbstractListeningExecutorService {

    @Override
    public void execute(Runnable runnable) {

 * it delegates to other components that potentially encounter problems. Then, the problem reporter can focus on
 * providing a simple error message, leaving the donkey work of creating a nice model problem to this component.
 *
 */
public interface ModelProblemCollector {

    ProblemCollector<ModelProblem> getProblemCollector();

/// tip

📥 `tokenUrl="token"` 🔗 ⚖ 📛 `token` 👈 👥 🚫 ✍. ⚫️ ⚖ 📛, ⚫️ 🌓 `./token`.

↩️ 👥 ⚙️ ⚖ 📛, 🚥 👆 🛠️ 🔎 `https://example.com/`, ⤴️ ⚫️ 🔜 🔗 `https://example.com/token`. ✋️ 🚥 👆 🛠️ 🔎 `https://example.com/api/v1/`, ⤴️ ⚫️ 🔜 🔗 `https://example.com/api/v1/token`.

⚙️ ⚖ 📛 ⚠ ⚒ 💭 👆 🈸 🚧 👷 🏧 ⚙️ 💼 💖 [⛅ 🗳](../../advanced/behind-a-proxy.md){.internal-link target=_blank}.

///

    try (Response response = client.newCall(request).execute()) {
      return response.body().string();
    }
  }

  public static void main(String[] args) throws IOException {
    GetExample example = new GetExample();
    String response = example.run("https://raw.github.com/square/okhttp/master/README.md");
    System.out.println(response);
  }

package lex

import (
	"go/build/constraint"
	"io"
	"os"
	"strings"
	"text/scanner"
	"unicode"

	"cmd/asm/internal/flags"
	"cmd/internal/objabi"
	"cmd/internal/src"
)

// A Tokenizer is a simple wrapping of text/scanner.Scanner, configured
// for our purposes and made a TokenReader. It forms the lowest level,
// turning text from readers into tokens.
type Tokenizer struct {
	tok  ScanToken
	s    *scanner.Scanner

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.