Iterator<? extends T> iterator) {
    if (iterator instanceof PeekingImpl) {
      // Safe to cast <? extends T> to <T> because PeekingImpl only uses T
      // covariantly (and cannot be subclassed to add non-covariant uses).
      @SuppressWarnings("unchecked")
      PeekingImpl<T> peeking = (PeekingImpl<T>) iterator;
      return peeking;
    }
    return new PeekingImpl<>(iterator);
  }

## Dependencies

### Added
- github.com/moby/sys/userns: [v0.1.0](https://github.com/moby/sys/tree/userns/v0.1.0)

### Changed
- github.com/vishvananda/netlink: [v1.3.0 → b1ce50c](https://github.com/vishvananda/netlink/compare/v1.3.0...b1ce50c)
- k8s.io/system-validators: v1.9.0 → v1.8.0

    `@ParametersAreNonnullByDefault` and all parameters and return types are
    never null unless explicitly annotated `@Nullable`.

 *  **Warning: this release is source-incompatible for Kotlin users.**
    Nullability was previously ambiguous and lenient but now the compiler will
    enforce strict null checks.

 *  New: The response message is now non-null. This is the "Not Found" in the

    ## Example

    ```python
    from fastapi import APIRouter, FastAPI

    app = FastAPI()
    router = APIRouter()


    @router.get("/users/", tags=["users"])
    async def read_users():
        return [{"username": "Rick"}, {"username": "Morty"}]


    app.include_router(router)
    ```
    """

    def __init__(
        self,

		h: &Header{
			Name:     "info.txt",
			Mode:     0600,
			Size:     0,
			Uid:      1000,
			Gid:      1000,
			ModTime:  time.Unix(1360602540, 0),
			Uname:    "slartibartfast",
			Gname:    "users",
			Typeflag: TypeReg,
		},
		fm: 0600,
	}}

	for i, v := range vectors {
		fi := v.h.FileInfo()
		h2, err := FileInfoHeader(fi, "")
		if err != nil {
			t.Error(err)
			continue
		}

//
//	// assign an email if the record is not found
//	db.Where(User{Name: "non_existing"}).Attrs(User{Email: "******@****.***"}).FirstOrInit(&user)
//	// user -> User{Name: "non_existing", Email: "******@****.***"}
//
//	// assign email regardless of if record is found
//	db.Where(User{Name: "jinzhu"}).Assign(User{Email: "******@****.***"}).FirstOrInit(&user)
//	// user -> User{Name: "jinzhu", Age: 20, Email: "******@****.***"}

   *
   * <ul>
   *   <li>it may split surrogate pairs
   *   <li>it may split characters and combining characters
   *   <li>it does not consider word boundaries
   *   <li>if truncating for display to users, there are other considerations that must be taken
   *       into account
   *   <li>the appropriate truncation indicator may be locale-dependent
   *   <li>it is safe to use non-ASCII characters in the truncation indicator

次の認証情報を使用します：

Username: `johndoe`
Password: `secret`

/// check | "確認"

コードのどこにも平文のパスワード"`secret`"はなく、ハッシュ化されたものしかないことを確認してください。

///

<img src="/img/tutorial/security/image08.png">

エンドポイント`/users/me/`を呼び出すと、次のようなレスポンスが得られます：

```JSON
{
  "username": "johndoe",
  "email": "******@****.***",
  "full_name": "John Doe",
  "disabled": false
}
```

      // This also avoids a race where if outputFuture is cancelled, it will call taskFuture.cancel,
      // which will call newFuture.setFuture(oldFuture), to allow the next task in the queue to run
      // without waiting for the user's executor to run our submitted Runnable. However, this can
      // interact poorly with the reentrancy-avoiding behavior of this executor - when the operation

   * serialize the copy. Other methods similar to this do not implement serialization at all for
   * this reason.
   *
   * <p><b>Java 8+ users:</b> many use cases for this method are better addressed by {@link
   * java.util.stream.Stream#map}. This method is not being deprecated, but we gently encourage you
   * to migrate to streams.
   */