@SuppressWarnings("unchecked")
        Cell<String, Integer, Character> cell = (Cell<String, Integer, Character>) element;
        table.put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }
      return table.cellSet();
    }

    abstract Table<String, Integer, Character> createTable();

    @Override
    @SuppressWarnings("unchecked")

        @SuppressWarnings("unchecked")
        Cell<String, Integer, Character> cell = (Cell<String, Integer, Character>) element;
        table.put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }
      return table.cellSet();
    }

    abstract Table<String, Integer, Character> createTable();

    @Override
    @SuppressWarnings("unchecked")

{* ../../docs_src/dependencies/tutorial011_an_py310.py hl[18] *}

这样就把依赖项“参数化”了，现在它内部带有属性 `checker.fixed_content` 的值 `"bar"`。

## 把实例作为依赖项 { #use-the-instance-as-a-dependency }

然后，我们可以在 `Depends(checker)` 中使用这个 `checker`，而不是 `Depends(FixedContentQueryChecker)`，因为依赖项是实例 `checker`，不是类本身。

解析依赖项时，**FastAPI** 会像这样调用 `checker`：

```Python
checker(q="somequery")
```

...并将其返回值作为依赖项的值，传给我们的*路径操作函数*中的参数 `fixed_content_included`：

   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings({"unchecked"}) // fully variant implementation (never actually produces any Es)
  public static <E> ImmutableSet<E> of() {
    return (ImmutableSet<E>) RegularImmutableSet.EMPTY;
  }

  /**

        }
    }

    @Override
    public BeanDesc getBeanDesc() {
        return beanDesc;
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> Constructor<T> getConstructor() {
        return (Constructor<T>) constructor;
    }

    @Override
    public Class<?>[] getParameterTypes() {
        return parameterTypes;

 *
 * @author Louis Wasserman
 */
@GwtIncompatible
public final class SafeTreeSet<E> implements Serializable, NavigableSet<E> {
  @SuppressWarnings("unchecked")
  private static final Comparator<Object> NATURAL_ORDER =
      (o1, o2) -> ((Comparable<Object>) o1).compareTo(o2);

  private final NavigableSet<E> delegate;

  public SafeTreeSet() {
    this(new TreeSet<E>());

          mapEntry("foo", 5),
          mapEntry("bar", 3),
          mapEntry("baz", 17),
          mapEntry("quux", 1),
          mapEntry("toaster", -2));
    }

    @SuppressWarnings("unchecked")
    @Override
    public Entry<String, Integer>[] createArray(int length) {
      return (Entry<String, Integer>[]) new Entry<?, ?>[length];
    }

    @Override

          mapEntry("foo", 5),
          mapEntry("bar", 3),
          mapEntry("baz", 17),
          mapEntry("quux", 1),
          mapEntry("toaster", -2));
    }

    @SuppressWarnings("unchecked")
    @Override
    public Entry<String, Integer>[] createArray(int length) {
      return (Entry<String, Integer>[]) new Entry<?, ?>[length];
    }

    @Override

    if (hasSameComparator && (elements instanceof ImmutableSortedSet)) {
      @SuppressWarnings("unchecked")
      ImmutableSortedSet<E> original = (ImmutableSortedSet<E>) elements;
      if (!original.isPartialView()) {
        return original;
      }
    }
    @SuppressWarnings("unchecked") // elements only contains E's; it's safe.
    E[] array = (E[]) Iterables.toArray(elements);

      this.adder = adder;
    }

    @Override
    @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
    public int add(int a, int b) {
      try {
        return adder.add(a, b);
      } catch (Exception e) { // sneaky checked exception
        // swallow!
        return 0;
      }
    }

    @Override
    public String toString() {