type NetworkError struct {
	Err error
}

func (n *NetworkError) Error() string {
	return n.Err.Error()
}

// Unwrap returns the error wrapped in NetworkError.
func (n *NetworkError) Unwrap() error {
	return n.Err
}

// Client - http based RPC client.
type Client struct {
	connected int32 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG

import java.util.TreeSet;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Run collection tests on wrappers from {@link Multimaps}.
 *
 * @author Jared Levy
 */
@GwtIncompatible // suite // TODO(cpovirk): set up collect/gwt/suites version
@NullUnmarked
@AndroidIncompatible // test-suite builders

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Test suites for wrappers in {@code Maps}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
@AndroidIncompatible // test-suite builders
public class MapsCollectionTest extends TestCase {
  public static Test suite() {

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

Was wir tun werden, ist, dies mit `Annotated` zu wrappen, sodass es zu:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python
q: Annotated[Union[str, None]] = None
```

////

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Test suites for wrappers in {@code Maps}.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
@AndroidIncompatible // test-suite builders
public class MapsCollectionTest extends TestCase {
  public static Test suite() {

      boolean completedWithFailure = setException(throwable);
      if (!completedWithFailure) {
        // Go up the causal chain to see if we've already seen this cause; if we have, even if
        // it's wrapped by a different exception, don't log it.
        boolean firstTimeSeeingThisException = addCausalChain(getOrInitSeenExceptions(), throwable);
        if (firstTimeSeeingThisException) {
          log(throwable);

 *       collection. This is a stronger guarantee than that of {@link
 *       Collections#unmodifiableCollection}, whose contents change whenever the wrapped collection
 *       is modified.
 *   <li><b>Null-hostility.</b> This collection will never contain a null element.
 *   <li><b>Deterministic iteration.</b> The iteration order is always well-defined, depending on

/// tip | Dica

Você pode usar qualquer outra biblioteca de banco de dados SQL ou NoSQL que quiser (em alguns casos chamadas de <abbr title="Object Relational Mapper – Mapeador Objeto-Relacional: um termo sofisticado para uma biblioteca onde algumas classes representam tabelas SQL e instâncias representam linhas nessas tabelas">"ORMs"</abbr>), o FastAPI não obriga você a usar nada. 😎

///

/// tip

You could use any other SQL or NoSQL database library you want (in some cases called <abbr title="Object Relational Mapper: a fancy term for a library where some classes represent SQL tables and instances represent rows in those tables">"ORMs"</abbr>), FastAPI doesn't force you to use anything. 😎

///

    assertThat(callCount.get()).isEqualTo(2);
  }

  /**
   * On a concurrent computation that throws an unchecked exception, all threads should get the
   * (wrapped) exception, with the loader called only once. The result should not be cached (a later
   * request should call the loader again).
   */