## Consequences

* We are incurring debt that will need to be paid later via deprecations or breaking changes to existing classes. The implementation for some Gradle types will be more complicated than an equivalent clean-sheet implementation.
* During code reviews that introduce new APIs, reviewers need to be mindful that all new properties are implemented with lazy types.

You can see more details in <a href="https://www.starlette.io/background/" class="external-link" target="_blank">Starlette's official docs for Background Tasks</a>.

## Caveat

        withModule<DowngradeXmlApisRule>("xalan:xalan")
        withModule<DowngradeXmlApisRule>("jaxen:jaxen")

        // We only need "failureaccess" of Guava's dependencies
        withLibraryDependencies<KeepDependenciesByNameRule>("com.google.guava:guava", setOf("failureaccess"))

        // We only need a few utility classes of this module
        withLibraryDependencies<DependencyRemovalByNameRule>("jcifs:jcifs", setOf("servlet-api"))

///

```Python hl_lines="10"
{!> ../../docs_src/header_param_models/tutorial002.py!}
```

////

If a client tries to send some **extra headers**, they will receive an **error** response.

For example, if the client tries to send a `tool` header with a value of `plumbus`, they will receive an **error** response telling them that the header parameter `tool` is not allowed:

```json
{

Start by forking the MinIO GitHub repository, make changes in a branch and then send a pull request. We encourage pull requests to discuss code changes. Here are the steps in details:

### Setup your MinIO GitHub Repository

Fork [MinIO upstream](https://github.com/minio/minio/fork) source repository to your own personal repository. Copy the URL of your MinIO fork (you will need it for the `git clone` command below).

```sh

///

## Await for messages and send messages

In your WebSocket route you can `await` for messages and send messages.

```Python hl_lines="48-52"
{!../../docs_src/websockets/tutorial001.py!}
```

You can receive and send binary, text, and JSON data.

## Try it

If your file is named `main.py`, run your application with:

# Advanced Dependencies

## Parameterized dependencies

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            sb.append(line);
            return seen < 2;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };

        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            sb.append(line);
            return seen < 2;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };

// start - starts separate goroutine for each TCP listener.  A valid new connection is passed to httpListener.acceptCh.
func (listener *httpListener) start() {
	// Closure to send acceptResult to acceptCh.
	// It returns true if the result is sent else false if returns when doneCh is closed.
	send := func(result acceptResult) bool {
		select {
		case listener.acceptCh <- result:
			// Successfully written to acceptCh
			return true