For example, if you want to read or manipulate the request body before it is processed by your application.

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases { #use-cases }

Some use cases include:

* Converting non-JSON request bodies to JSON (e.g. [`msgpack`](https://msgpack.org/index.html)).

}

// NewDummyDataGen returns a ReadSeeker over the first `totalLength`
// bytes from the infinite stream consisting of repeated
// concatenations of `alphabets`.
//
// The skipOffset (generally = 0) can be used to skip a given number
// of bytes from the beginning of the infinite stream. This is useful
// to compare such streams of bytes that may be split up, because:
//
// Given the function:
//
//	f := func(r io.Reader) string {

                }
            }

            // Process objects (files)
            for (final S3Object s3Object : response.contents()) {
                final String objectKey = s3Object.key();
                // Skip directory markers (objects ending with /)
                if (!objectKey.endsWith("/")) {
                    final String fileName = getName(objectKey);
                    final ZonedDateTime lastModified =

//	        SignedHeaders=signedHeaders, Signature=signature
func parseSignV4(v4Auth string, region string, stype serviceType) (sv signValues, aec APIErrorCode) {
	// credElement is fetched first to skip replacing the space in access key.
	credElement := strings.TrimPrefix(strings.Split(strings.TrimSpace(v4Auth), ",")[0], signV4Algorithm)
	// Replace all spaced strings, some clients can send spaced

		}
		if len(prefix) > 0 && len(rule.Filter.Prefix) > 0 {
			// incoming prefix must be in rule prefix
			if !recursive && !strings.HasPrefix(prefix, rule.Filter.Prefix) {
				continue
			}
			// If recursive, we can skip this rule if it doesn't match the tested prefix or level below prefix
			// does not match
			if recursive && !strings.HasPrefix(rule.Prefix(), prefix) && !strings.HasPrefix(prefix, rule.Prefix()) {
				continue
			}
		}

        // 1. It's a merge commit.
        // 2. One of its parent commits is from master only.
        // 3. Another parent commit is not from master but from release branch.
        // Otherwise, skip this commit.
        List<String> p1Branches = branchesOf(parentCommits.get(0));
        List<String> p2Branches = branchesOf(parentCommits.get(1));

        System.out.println(commit + " parents: " + parentCommits);

Those parameters are what **FastAPI** will use to "solve" the dependency.

In both cases, it will have:

* An optional `q` query parameter that is a `str`.
* A `skip` query parameter that is an `int`, with a default of `0`.
* A `limit` query parameter that is an `int`, with a default of `100`.

In both cases the data will be converted, validated, documented on the OpenAPI schema, etc.

Esses parâmetros são utilizados pelo **FastAPI** para "definir" a dependência.

Em ambos os casos teremos:

* Um parâmetro de consulta `q` opcional do tipo `str`.
* Um parâmetro de consulta `skip` do tipo `int`, com valor padrão `0`.
* Um parâmetro de consulta `limit` do tipo `int`, com valor padrão `100`.

Os dados serão convertidos, validados, documentados no esquema da OpenAPI e etc nos dois casos.

     *
     * @param response the response object to populate
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doRecv(Response response) throws IOException;

    /**
     * Skips an unexpected or unrecognized message.
     *
     * @throws IOException if an I/O error occurs
     */
    protected abstract void doSkip() throws IOException;

    /**

        if (flowControlError) {
          source.skip(remainingByteCount)
          closeLater(ErrorCode.FLOW_CONTROL_ERROR)
          return
        }

        // Discard data received after the stream is finished. It's probably a benign race.
        if (finished) {
          source.skip(remainingByteCount)
          return
        }