assertThat("Thu, 01 Jan 1970 00:00:00".toHttpDateOrNull()).isNull()
    // Missing seconds treated as bad.
    assertThat("Thu, 01 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()
    // Extra spaces treated as bad.
    assertThat("Thu,  01 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()
    // Missing leading zero treated as bad.
    assertThat("Thu, 1 Jan 1970 00:00 GMT".toHttpDateOrNull()).isNull()

 *     .addEquivalenceGroup("world", "wor" + "ld")
 *     .test();
 * }</pre>
 *
 * <p>Note that testing {@link Object#equals(Object)} is more simply done using the {@link
 * EqualsTester}. It includes an extra test against an instance of an arbitrary class without having
 * to explicitly add another equivalence group.
 *
 * @author Gregory Kick
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 *     .addEquivalenceGroup("world", "wor" + "ld")
 *     .test();
 * }</pre>
 *
 * <p>Note that testing {@link Object#equals(Object)} is more simply done using the {@link
 * EqualsTester}. It includes an extra test against an instance of an arbitrary class without having
 * to explicitly add another equivalence group.
 *
 * @author Gregory Kick
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

    assertFalse(future.isDone());
    assertFalse(future.isCancelled());

    CountDownLatch successLatch = new CountDownLatch(1);

    // Run cancellation in a separate thread as an extra thread-safety test.
    new Thread(
            () -> {
              assertThrows(CancellationException.class, future::get);
              successLatch.countDown();
            })
        .start();

    // deal with camel conversion
    StringBuilder out = null;
    int i = 0;
    int j = -1;
    while ((j = wordBoundary.indexIn(s, ++j)) != -1) {
      if (i == 0) {
        // include some extra space for separators
        out = new StringBuilder(s.length() + 4 * format.wordSeparator.length());
        out.append(format.normalizeFirstWord(s.substring(i, j)));
      } else {

## `Header`-Parameter deklarieren

Dann deklarieren Sie Ihre Header-Parameter, auf die gleiche Weise, wie Sie auch `Path`-, `Query`-, und `Cookie`-Parameter deklarieren.

Der erste Wert ist der Typ. Sie können `Header` die gehabten Extra Validierungs- und Beschreibungsparameter hinzufügen. Danach können Sie einen Defaultwert vergeben:

//// tab | Python 3.10+

```Python hl_lines="9"
{!> ../../docs_src/header_params/tutorial001_an_py310.py!}
```

import com.google.common.escape.CharEscaper;
import com.google.common.escape.Escaper;
import com.google.common.escape.UnicodeEscaper;
import java.io.IOException;
import junit.framework.Assert;

/**
 * Extra assert methods for testing Escaper implementations.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class EscaperAsserts {
  private EscaperAsserts() {}

  /**

      while (idx < encodedLen) {
        // Read all the children
        idx += doParseTrieToBuilder(stack, encoded, idx, builder);

        if (encoded.charAt(idx) == '?' || encoded.charAt(idx) == ',') {
          // An extra '?' or ',' after a child node indicates the end of all children of this node.
          idx++;
          break;
        }
      }
    }

    stack.pop();
    return idx - start;
  }

import com.google.common.escape.CharEscaper;
import com.google.common.escape.Escaper;
import com.google.common.escape.UnicodeEscaper;
import java.io.IOException;
import junit.framework.Assert;

/**
 * Extra assert methods for testing Escaper implementations.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class EscaperAsserts {
  private EscaperAsserts() {}

  /**

        * **FastAPI**: (uses Starlette) an API microframework with several additional features for building APIs, with data validation, etc.

* **Uvicorn**:
    * Will have the best performance, as it doesn't have much extra code apart from the server itself.