* }
 * }</pre>
 *
 * @author Ben Yu
 * @since 12.0
 */
@ElementTypesAreNonnullByDefault
/*
 * A nullable bound would let users create a TypeParameter instance for a parameter with a nullable
 * bound. However, it would also let them create `new TypeParameter<@Nullable T>() {}`, which
 * wouldn't behave as users might expect. Additionally, it's not clear how the TypeToken API could

        ctClass.metadata
            ?.let { KotlinClassMetadata.read(it) }
            ?.let { query(it) }
            ?: defaultResult

    private
    val CtClass.metadata: Metadata?
        get() = ctAnnotation<Metadata>()?.let { annotation ->
            Metadata(
                kind = annotation.getMemberValue("k")?.intValue ?: 1,

        buildReceiptString()
            ?.let(BuildReceipt::readBuildReceiptFromString)
            ?.let { buildReceipt ->
                buildReceipt["buildTimestamp"] as String
            }
    }

    override fun getDisplayName(): String =
        "the build timestamp extracted from the build receipt".let {
            when {

                KTypeProjection(
                    variance = KVariance.INVARIANT,
                    type = keyArgument.type?.let(mappingConversionForKeys::convertType)
                ),
                KTypeProjection(
                    variance = KVariance.INVARIANT,
                    type = valueArgument.type?.let(mappingConversionForValues::convertType)
                )
            )
        )
    }

 */
function summaryTable(statistics, title) {
    let preppedStatistics = statistics.filter(s => s.files.length > 0)
        .sort(s => -(s.additions + s.deletions));

    let totalAdditions = Object.values(preppedStatistics).reduce((acc, summary) => acc + summary.additions, 0);
    let totalDeletions = Object.values(preppedStatistics).reduce((acc, summary) => acc + summary.deletions, 0);

## Let's Encrypt

Antes de Let's Encrypt, esses certificados HTTPS eram vendidos por terceiros confiáveis.

O processo de aquisição de um desses certificados costumava ser complicado, exigia bastante papelada e os certificados eram bastante caros.

Mas então <a href="https://letsencrypt.org/" class="external-link" target="_blank">Let's Encrypt</a> foi criado.

 */
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);

            .accept(query.visitor, null)
            ?: query.defaultValue


    fun <T : Any?> executeQuery(apiSourceFile: ApiSourceFile.Kotlin, transform: (KtFile) -> T): T =
        apiSourceFile.normalizedPath.let { sourceNormalizedPath ->
            openKotlinCompilationUnitsByRoot
                .computeIfAbsent(apiSourceFile.currentSourceRoot) {
                    KotlinSourceParser().parseSourceRoots(

## 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.

    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) ->