return Iterators.forArray(1, 2, 3);
      }
    }.test();
  }

  /*
   * TODO(cpovirk): Test forArray with ListIteratorTester (not just IteratorTester), including with
   * a start position other than 0.
   */

  public void testForEnumerationEmpty() {
    Enumeration<Integer> enumer = enumerate();
    Iterator<Integer> iter = Iterators.forEnumeration(enumer);

    assertFalse(iter.hasNext());

			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidRangePartNumber), r.URL)
			return
		}

		rs, rangeErr = parseRequestRangeSpec(rangeHeader)
		// Handle only errInvalidRange. Ignore other
		// parse error and treat it as regular Get
		// request like Amazon S3.
		if errors.Is(rangeErr, errInvalidRange) {
			writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidRange), r.URL)
			return
		}
	}

pkg crypto/cipher, func NewOFB(Block, []uint8) Stream
pkg crypto/cipher, method (StreamReader) Read([]uint8) (int, error)
pkg crypto/cipher, method (StreamWriter) Close() error
pkg crypto/cipher, method (StreamWriter) Write([]uint8) (int, error)
pkg crypto/cipher, type Block interface { BlockSize, Decrypt, Encrypt }
pkg crypto/cipher, type Block interface, BlockSize() int

通过这种方式，我们确保数据库会话在请求后始终关闭，即使在处理请求时出现异常也会关闭。

///

### 关于`request.state`

`request.state`是每个`Request`对象的属性。它用于存储附加到请求本身的任意对象，例如本例中的数据库会话。您可以在[Starlette 的关于`Request`state](https://www.starlette.io/requests/#other-state)的文档中了解更多信息。

对于这种情况下，它帮助我们确保在整个请求中使用单个数据库会话，然后关闭（在中间件中）。

### 使用`yield`依赖项与使用中间件的区别

在此处添加**中间件**与`yield`的依赖项的作用效果类似，但也有一些区别：

* 中间件需要更多的代码并且更复杂一些。
* 中间件必须是一个`async`函数。

	type ColumnStruct2 struct {
		gorm.Model
		Name         string
		StringBool   bool // change existing boolean column from string to boolean
		SmallintBool bool // change existing boolean column from smallint or other to boolean
	}

	DB.Migrator().DropTable(&ColumnStruct{})

	if err := DB.AutoMigrate(&ColumnStruct{}); err != nil {
		t.Errorf("Failed to migrate, got %v", err)
	}

	MOVQ CR0, DX // 0f20c2
	MOVQ CR4, DI // 0f20e7
	MOVQ AX, CR0 // 0f22c0
	MOVQ DX, CR0 // 0f22c2
	MOVQ DI, CR4 // 0f22e7
	MOVQ DR0, AX // 0f21c0
	MOVQ DR6, DX // 0f21f2
	MOVQ DR7, SI // 0f21fe
	// Test other movtab entries.
	PUSHQ GS // 0fa8
	PUSHQ FS // 0fa0
	POPQ FS  // 0fa1
	POPQ GS  // 0fa9
	// All instructions below semantically have unsigned operands,
	// but previous assembler permitted negative arguments.

	}
	if err != nil {
		return err
	}
	t := time.Now().UTC()
	c.lastConnect.Store(&t)
	// Signal that we are reconnected, update state and handle messages.
	// Prevent other connections from connecting while we process.
	c.reconnectMu.Lock()
	if c.remoteID != nil {
		c.reconnected()
	}
	rid := uuid.UUID(req.ID)
	c.remoteID = &rid

	// Handle incoming messages until disconnect.

   * Glob patterns must be unique, if there's a clash assign to the most
     popular format
   * The main mime type should be the canonical one, use aliases for any
     other widely used forms
   * Where there's a hierarchy in the types, list it via a parent
   * Highly specific magic matches get a high priority
   * General magic matches which could trigger a false-positive need
     a low one

	if hr.Before.Drives[0].State != madmin.DriveStateMissing {
		t.Fatalf("Unexpected drive state: %v", hr.Before.Drives[0].State)
	}

	// Check the state of all other disks (should be ok)
	for i, h := range append(hr.Before.Drives[1:], hr.After.Drives...) {
		if h.State != madmin.DriveStateOk {
			t.Fatalf("Unexpected drive state (%d): %v", i+1, h.State)
		}
	}

         * element anymore. Otherwise, when we remove from the old iterator, we may be invalidating
         * the new one. The result is a ConcurrentModificationException or other bad behavior.
         *
         * (If we decide that we really, really hate allocating two Iterators per cycle instead of
         * one, we can optimistically store the new Iterator and then be willing to throw it out if