}

private fun checkSupportResponse(
  name: String,
  response: Response?,
) {
  response?.apply {
    require(networkResponse == null) { "$name.networkResponse != null" }
    require(cacheResponse == null) { "$name.cacheResponse != null" }
    require(priorResponse == null) { "$name.priorResponse != null" }
  }
}

fun Response.Builder.commonPriorResponse(priorResponse: Response?) =
  apply {

  - commit
  - comment_added

automations:

  # If a PR is very complex, require 2 approvals
  complex_changes:
    if:
      - {{ ('complex_changes' | isEnabledAutomation(pr)) }}
      - {{ branch | estimatedReviewTime >= 40 }}
      - {{ files | length >= 35 }}
      - {{ includes_src_changes }}
    run:
      - action: set-required-approvals@v1
        args:
          approvals: 2

                // Stubbed top-level function IR symbols (from other source files in the module) require a parent facade class to be
                // generated, which requires a container source to be provided. Without a facade class, function IR symbols will have
                // an `IrExternalPackageFragment` parent, which trips up code generation during IR lowering.

    require(keepAliveDuration > 0L) { "keepAliveDuration <= 0: $keepAliveDuration" }
  }

  fun idleConnectionCount(): Int {
    return connections.count {
      it.withLock { it.calls.isEmpty() }
    }
  }

  fun connectionCount(): Int {
    return connections.size
  }

  /**

   * explicitly closed.
   */
  fun truncateLastFrame(length: Int): Http2Writer {
    val lastFrame = outFrames.removeAt(outFrames.size - 1)
    require(length < bytesOut.size - lastFrame.start)

    // Move everything from bytesOut into a new buffer.
    val fullBuffer = Buffer()
    bytesOut.read(fullBuffer, bytesOut.size)

    if (flushHeaders) {
      connection.flush()
    }
  }

  fun enqueueTrailers(trailers: Headers) {
    this.withLock {
      check(!sink.finished) { "already finished" }
      require(trailers.size != 0) { "trailers.size() == 0" }
      this.sink.trailers = trailers
    }
  }

  fun readTimeout(): Timeout = readTimeout

  fun writeTimeout(): Timeout = writeTimeout

It has a `GET` operation that could return an error.

It has a `POST` operation that could return several errors.

Both *path operations* require an `X-Token` header.

=== "Python 3.10+"

    ```Python
    {!> ../../../docs_src/app_testing/app_b_an_py310/main.py!}
    ```

=== "Python 3.9+"

    ```Python

      // seconds are not supported by this syntax.
      require(year >= 1601)
      require(month != -1)
      require(dayOfMonth in 1..31)
      require(hour in 0..23)
      require(minute in 0..59)
      require(second in 0..59)

      GregorianCalendar(UTC).apply {
        isLenient = false
        set(Calendar.YEAR, year)

        val assignmentRValue = fir.rValue
        if (expression is KtOperationReferenceExpression &&
            assignmentRValue.source?.kind is KtFakeSourceElementKind.DesugaredAugmentedAssign
        ) {
            require(assignmentRValue is FirResolvable) {
                "Rvalue of desugared compound assignment should be resolvable, but it was ${assignmentRValue::class}"
            }

      apply {
        val maxAgeSeconds = maxAge.inWholeSeconds
        require(maxAgeSeconds >= 0) { "maxAge < 0: $maxAgeSeconds" }
        this.maxAgeSeconds = maxAgeSeconds.commonClampToInt()
      }

    fun maxStale(maxStale: Duration) =
      apply {
        val maxStaleSeconds = maxStale.inWholeSeconds
        require(maxStaleSeconds >= 0) { "maxStale < 0: $maxStaleSeconds" }