## Technical Details { #technical-details }

/// tip

If you are already using **FastAPI** version **0.99.0 or above**, you can probably **skip** these details.

They are more relevant for older versions, before OpenAPI 3.1.0 was available.

You can consider this a brief OpenAPI and JSON Schema **history lesson**. 🤓

///

/// warning

	// Type '7' is reserved.
	TypeCont = '7'

	// Type 'x' is used by the PAX format to store key-value records that
	// are only relevant to the next file.
	// This package transparently handles these types.
	TypeXHeader = 'x'

	// Type 'g' is used by the PAX format to store key-value records that
	// are relevant to all subsequent files.
	// This package only supports parsing and composing such headers,

produce it from the Program, in the form of source code under the
terms of section 4, provided that you also meet all of these conditions:

    a) The work must carry prominent notices stating that you modified
    it, and giving a relevant date.

    b) The work must carry prominent notices stating that it is
    released under this License and any conditions added under section
    7.  This requirement modifies the requirement in section 4 to

{* ../../docs_src/handling_errors/tutorial001.py hl[1] *}

### Raise an `HTTPException` in your code { #raise-an-httpexception-in-your-code }

`HTTPException` is a normal Python exception with additional data relevant for APIs.

Because it's a Python exception, you don't `return` it, you `raise` it.

// but can be replaced atomically.
//
// This function should only be used with
// - GetBucketInfo
// - ListBuckets
// For all other bucket specific metadata, use the relevant
// calls implemented specifically for each of those features.
func (sys *BucketMetadataSys) Get(bucket string) (BucketMetadata, error) {
	if isMinioMetaBucketName(bucket) {

```
KEY:
etcd  federate multiple clusters for IAM and Bucket DNS

ARGS:

    be used to make canonical URLs for the cache that omit insignificant query parameters or other
    irrelevant data.

    This feature may be used with `POST` requests to cache their responses. In such cases the
    request body is not used to determine the cache key, so you must manually add cache-relevant
    data to the override URL. For example, you could add a `request-body-sha256` query parameter so

const usePkgCache = true

var (
	pkgCache = map[string]*apiPackage{} // map tagKey to package
	pkgTags  = map[string][]string{}    // map import dir to list of relevant tags
)

// tagKey returns the tag-based key to use in the pkgCache.
// It is a comma-separated string; the first part is dir, the rest tags.
// The satisfied tags are derived from context but only those that

 * context (such as an XML document). Typically (but not always), the inverse process of
 * "unescaping" the text is performed automatically by the relevant parser.
 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the

 * context (such as an XML document). Typically (but not always), the inverse process of
 * "unescaping" the text is performed automatically by the relevant parser.
 *
 * <p>For example, an XML escaper would convert the literal string {@code "Foo<Bar>"} into {@code
 * "Foo&lt;Bar&gt;"} to prevent {@code "<Bar>"} from being confused with an XML tag. When the