このようにして依存関係を「パラメータ化」できます。いまや `"bar"` が属性 `checker.fixed_content` として中に保持されています。

## インスタンスを依存関係として使う { #use-the-instance-as-a-dependency }

その後、`Depends(FixedContentQueryChecker)` の代わりに `Depends(checker)` でこの `checker` を使えます。依存関係はクラスそのものではなく、インスタンスである `checker` だからです。

依存関係を解決するとき、**FastAPI** はこの `checker` を次のように呼び出します:

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

{* ../../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`：

These custom validators are for things that can be checked with **only** the **same data** provided in the request.

///

### Understand that Code { #understand-that-code }

   * RuntimeException}, {@link Error}, {@code declaredType1}, or {@code declaredType2}.
   *
   * @param throwable the Throwable to possibly propagate
   * @param declaredType1 any checked exception type declared by the calling method
   * @param declaredType2 any other checked exception type declared by the calling method
   * @deprecated Use a combination of two calls to {@link #throwIfInstanceOf} and one call to {@link

            for (String s : footer) {
                writer.writeln(s);
            }
        }
        writer.flush();
    }

    /**
     * Checks if parts of the passed in comment can be used as header comment.
     * This method checks whether a header comment can be defined (i.e. whether
     * this is the first comment in the loaded file). If this is the case, it is

            for (String s : footer) {
                writer.writeln(s);
            }
        }
        writer.flush();
    }

    /**
     * Checks if parts of the passed in comment can be used as header comment.
     * This method checks whether a header comment can be defined (i.e. whether
     * this is the first comment in the loaded file). If this is the case, it is

    public T get() {
      // A 2-field variant of Double Checked Locking.
      if (!initialized) {
        synchronized (lock) {
          if (!initialized) {
            T t = delegate.get();
            value = t;
            initialized = true;
            return t;
          }
        }
      }
      // This is safe because we checked `initialized`.
      return uncheckedCastNullableTToT(value);
    }

        return id;
    }

    /**
     * Set a filter value based on checked state (add if checked, remove if unchecked)
     */
    function setFilter(array, value, checked) {
        var index = array.indexOf(value);
        if (checked && index === -1) {
            array.push(value);
        } else if (!checked && index !== -1) {
            array.splice(index, 1);
        }
    }

    /**

    // fixtures are allowed to use whatever dependencies they want...
    return
  }
  pluginManager.withPlugin('java') {
    checkDeps(configurations.compileClasspath)
    checkDeps(configurations.testCompileClasspath)
  }

     */
    String getConnectedShare();

    /**
     * Checks if this tree handle refers to the same tree as another
     * @param th the tree handle to compare with
     * @return whether the handles refer to the same tree
     */
    boolean isSameTree(SmbTreeHandle th);

    /**
     * Checks if this tree handle uses SMB2 or later protocol
     * @return whether this tree handle uses SMB2+
     */