*/
function computeStatistics(groupedFiles, fileMetadatas) {
    let totalAdditions = 0;
    let totalDeletions = 0
    let totalChangedFiles = 0;

    let summaries = [...groupedFiles.values()];
    Object.values(summaries).forEach(summary => {
        summary.additions = 0;
        summary.deletions = 0;

        summary.files.forEach(file => {
            let fileMetadata = metadataFor(fileMetadatas, file);

        // psiBased
        (symbol.psi?.containingFile as? KtFile)?.let { ktFile ->
            with(analysisSession) {
                return ktFile.getFileSymbol()
            }
        }
        // descriptorBased
        val descriptor = symbol.containingSymbolOrSelf.getDescriptor()
        val ktFile = descriptor?.let(DescriptorToSourceUtils::getContainingFile) ?: return null
        with(analysisSession) {

    private
    var closed = false

    fun type(sourceName: String): ApiType? = open {
        apiTypesBySourceName.computeIfAbsent(sourceName) {
            repository.classBytesFor(sourceName)?.let { apiTypeFor(sourceName) { it } }
        }?.invoke()
    }

    internal
    fun allTypes(): Sequence<ApiType> = open {
        repository.allClassesBytesBySourceName().map { (sourceName, classBytes) ->

* Nginx
* HAProxy

## Let's Encrypt

Vor Let's Encrypt wurden diese **HTTPS-Zertifikate** von vertrauenswürdigen Dritten verkauft.

Der Prozess zum Erwerb eines dieser Zertifikate war früher umständlich, erforderte viel Papierarbeit und die Zertifikate waren ziemlich teuer.

Aber dann wurde **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** geschaffen.

## Use Case

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

The same models are shared among requests, so, it's not one model per request, or one per user or something similar.

* Nginx
* HAProxy

## Let's Encrypt

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **<a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a>** was created.

     */
    private inline fun <reified T : FirCallableDeclaration> T.unwrapSubstitutionOverrideIfNeeded(): T? {
        unwrapUseSiteSubstitutionOverride()?.let { return it }

        unwrapInheritanceSubstitutionOverrideIfNeeded()?.let { return it }

        return null
    }

    /**
     * Use-site substitution override happens in situations like this:
     *
     * ```

    System.setErr(object : PrintStream(OutputStream.nullOutputStream()) {})
  }

  fun uninstall() {
    originalSystemOut.let {
      System.setOut(it)
    }
    originalSystemErr.let {
      System.setErr(it)
    }
  }

## Testing: extended example

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file

Let's continue with the same file structure as before:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

            substitutor.substitute(returnType),
            receiverType?.let { substitutor.substitute(it) },
            valueParameters.map { valueParameter ->
                KtFe10VariableLikeSignature<KtValueParameterSymbol>(
                    valueParameter.symbol,
                    substitutor.substitute(valueParameter.returnType),
                    valueParameter.receiverType?.let { substitutor.substitute(it) }
                )
            }