import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Provides utility methods for working with {@linkplain File files}.
 *
 * <p>{@link java.nio.file.Path} users will find similar utilities in {@link MoreFiles} and the
 * JDK's {@link java.nio.file.Files} class.
 *
 * @author Chris Nokleberg
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible

 *
 * <p><b>Note:</b> by default, the returned cache uses equality comparisons (the {@link
 * Object#equals equals} method) to determine equality for keys or values. However, if {@link
 * #weakKeys} was specified, the cache uses identity ({@code ==}) comparisons instead for keys.
 * Likewise, if {@link #weakValues} or {@link #softValues} was specified, the cache uses identity
 * comparisons for values.
 *

public final class Longs {
  private Longs() {}

  /**
   * The number of bytes required to represent a primitive {@code long} value.
   *
   * <p><b>Java 8+ users:</b> use {@link Long#BYTES} instead.
   */
  public static final int BYTES = Long.SIZE / Byte.SIZE;

  /**
   * The largest power of two that can be represented as a {@code long}.
   *
   * @since 10.0
   */
  public static final long MAX_POWER_OF_TWO = 1L << (Long.SIZE - 2);

public final class Longs {
  private Longs() {}

  /**
   * The number of bytes required to represent a primitive {@code long} value.
   *
   * <p><b>Java 8+ users:</b> use {@link Long#BYTES} instead.
   */
  public static final int BYTES = Long.SIZE / Byte.SIZE;

  /**
   * The largest power of two that can be represented as a {@code long}.
   *
   * @since 10.0
   */
  public static final long MAX_POWER_OF_TWO = 1L << (Long.SIZE - 2);

 *      <th>Required?</th>
 *      <th>Notes</th>
 *  </tr>
 *  <tr>
 *      <td>goal</td>
 *      <td>name = "&lt;goal-name&gt;"</td>
 *      <td>Yes</td>
 *      <td>The name for the Mojo that users will reference from the command line to execute the Mojo directly,
 *      or inside a POM in order to provide Mojo-specific configuration.</td>
 *  </tr>
 *  <tr>
 *      <td>implementation</td>

   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *
   * <p><b>Java 9 users:</b> use {@code java.util.Objects.requireNonNullElse(first, second)}
   * instead.
   *
   * @return {@code first} if it is non-null; otherwise {@code second} if it is non-null

import jcifs.Address;
import jcifs.CIFSContext;
import jcifs.NetbiosAddress;
import jcifs.NetbiosName;


/**
 * This class represents a NetBIOS over TCP/IP address. Under normal
 * conditions, users of jCIFS need not be concerned with this class as
 * name resolution and session services are handled internally by the smb package.
 * 
 * <p>
 * Applications can use the methods <code>getLocalHost</code>,

- kube-apiserver:

```Python hl_lines="2  15  26"
{!../../docs_src/sql_databases/sql_app/models.py!}
```

当访问 user 中的属性`items`时，如 中`my_user.items`，它将有一个`Item`SQLAlchemy 模型列表（来自`items`表），这些模型具有指向`users`表中此记录的外键。

当您访问`my_user.items`时，SQLAlchemy 实际上会从`items`表中的获取一批记录并在此处填充进去。

同样，当访问 Item中的属性`owner`时，它将包含表中的`User`SQLAlchemy 模型`users`。使用`owner_id`属性/列及其外键来了解要从`users`表中获取哪条记录。

## 创建 Pydantic 模型

现在让我们查看一下文件`sql_app/schemas.py`。

/// tip

 * that is already in the desired state.
 *
 * <p>When testing code that uses this class, use {@link #createUnstarted(Ticker)} or {@link
 * #createStarted(Ticker)} to supply a fake or mock ticker. This allows you to simulate any valid
 * behavior of the stopwatch.
 *
 * <p><b>Note:</b> This class is not thread-safe.
 *
 * <p><b>Warning for Android users:</b> a stopwatch with default behavior may not continue to keep