return request.build()
}

private fun Main.mediaType(): MediaType? {
  val mimeType =
    headers?.let {
      for (header in it) {
        val parts = header.split(':', limit = 2)
        if ("Content-Type".equals(parts[0], ignoreCase = true)) {
          return@let parts[1].trim()
        }
      }
      return@let null
    } ?: "application/x-www-form-urlencoded"

  return mimeType.toMediaTypeOrNull()
}

            descriptor?.let { KtFe10AnnotationsList.create(it.annotations, analysisContext) } ?: KtEmptyAnnotationsList(token)
        }

    @OptIn(KtAnalysisApiInternals::class)
    override fun createPointer(): KtSymbolPointer<KtPropertySetterSymbol> = withValidityAssertion {
        KtPsiBasedSymbolPointer.createForSymbolFromPsi<KtPropertySymbol>(propertyPsi)?.let(::KtPropertySetterSymbolPointer)

        (value as? String)?.let { opr ->
            evalUnaryOp(
                function.name.asString(),
                kind.toCompileTimeType(),
                opr
            )?.let {
                return it.toConstantValueKind().toLiteralExpression(source, it)
            }
        }
        return kind.convertToNumber(value)?.let { opr ->
            evalUnaryOp(

            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) }
                )
            }

Вот некоторые варианты, которые вы можете использовать в качестве такого прокси-сервера:

* Traefik (может обновлять сертификаты)
* Caddy (может обновлять сертификаты)
* Nginx
* HAProxy

## Let's Encrypt (центр сертификации)

До появления Let's Encrypt **сертификаты HTTPS** приходилось покупать у третьих сторон.

Процесс получения такого сертификата был трудоёмким, требовал предоставления подтверждающих документов и сертификаты стоили дорого.

                        psiElements.firstIsInstanceOrNull<PsiField>()?.let {
                            bindings.put(FIELD_FOR_PROPERTY, fir, Type.getType(getBinaryPresentationWithCorrection(it.type)) to it.name)
                        }
                    }
                    fir.getter?.let { getter ->
                        methods.singleOrNull { it.returnType != PsiType.VOID }?.let {

            descriptor?.let { KtFe10AnnotationsList.create(it.annotations, analysisContext) } ?: KtEmptyAnnotationsList(token)
        }

    @OptIn(KtAnalysisApiInternals::class)
    override fun createPointer(): KtSymbolPointer<KtPropertyGetterSymbol> = withValidityAssertion {
        KtPsiBasedSymbolPointer.createForSymbolFromPsi<KtPropertySymbol>(propertyPsi)?.let(::KtPropertyGetterSymbolPointer)

            is KtBinaryExpression -> {
                handleAsCompoundAssignment(this, unwrappedPsi)?.let { return@with it }
                handleAsFunctionCall(this, unwrappedPsi)
            }
            is KtUnaryExpression -> {
                handleAsIncOrDecOperator(this, unwrappedPsi)?.let { return@with it }
                handleAsFunctionCall(this, unwrappedPsi)
            }

        // 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) {

## An app with callbacks

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

The user of your API (an external developer) will create an invoice in your API with a POST request.

Then your API will (let's imagine):