///

We are going to include this `APIRouter` in the main `FastAPI` app, but first, let's check the dependencies and another `APIRouter`.

## Dependencies { #dependencies }

We see that we are going to need some dependencies used in several places of the application.

So we put them in their own `dependencies` module (`app/dependencies.py`).

termcolor == 2.3.0
wrapt == 1.16.0
tblib == 2.0.0
ml_dtypes >= 0.5.1, < 0.6.0
auditwheel >= 6.1.0
# Install tensorboard, and keras
# Note that here we want the latest version that matches TF major.minor version
# Note that we must use nightly here as these are used in nightly jobs
# For release jobs, we will pin these on the release branch
keras-nightly ~= 3.10.0.dev
tb-nightly ~= 2.20.0.a

Let's look at how we can make that work.

## pytest.mark.anyio { #pytest-mark-anyio }

// of the payload and verify that it matches the expected signature value.
//
// The last chunk is *always* 0-sized. So, we must only return io.EOF if we have encountered
// a chunk with a chunk size = 0. However, this chunk still has a signature and we must
// verify it.
const maxChunkSize = 16 << 20 // 16 MiB

// Read - implements `io.Reader`, which transparently decodes

{* ../../docs_src/settings/app02_an_py39/test_main.py hl[9:10,13,21] *}

In the dependency override we set a new value for the `admin_email` when creating the new `Settings` object, and then we return that new object.

Then we can test that it is used.

## Reading a `.env` file { #reading-a-env-file }

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

Here we are using `Query()` because this is a **query parameter**. Later we will see others like `Path()`, `Body()`, `Header()`, and `Cookie()`, that also accept the same arguments as `Query()`.

But in most of the cases where we need to do something like this, we want the model just to **filter/remove** some of the data as in this example.

# the hashes of all the branch heads, so we can use a hash of
# all those branch names and heads as a conservative snapshot
# of the entire remote repo state, and use that as the tag sum.
# Any change on the server then invalidates the tag sum,
# even if it didn't have anything to do with tags, but at least
# we will avoid re-cloning a server when there have been no
# changes at all.
#

		// There is at least one SSE-S3 single-part object.
		// For all SSE-S3 single-part objects we have to
		// fetch their decryption keys. We do this using
		// a Bulk-Decryption API call, if available.
		keys, err := crypto.S3.UnsealObjectKeys(ctx, k, metadata, buckets, names)
		if err != nil {
			return err
		}

		// Now, we have to decrypt the ETags of SSE-S3 single-part

	errOutdatedXLMeta = errors.New("outdated XL meta")
	errPartCorrupt    = errors.New("part corrupt")
	errPartMissing    = errors.New("part missing")
)

// Only heal on disks where we are sure that healing is needed. We can expand
// this list as and when we figure out more errors can be added to this list safely.
func shouldHealObjectOnDisk(erErr error, partsErrs []int, meta FileInfo, latestMeta FileInfo) (bool, bool, error) {