sourceDirs()
                }

            require(sourceDirs.isNotEmpty()) {
                "Expected source directories but got none"
            }

            val subprojectSourcePath = "org/gradle/StartParameter.java"
            val subprojectFound = sourceDirs.find { it.resolve(subprojectSourcePath).isFile }
            require(subprojectFound != null) {

class CircularReferences {

    private
    val refs = ReferenceOpenHashSet<Any>()

    fun enter(reference: Any) {
        require(refs.add(reference))
    }

    operator fun contains(reference: Any) =
        refs.contains(reference)

    fun leave(reference: Any) {
        require(refs.remove(reference))
    }

     * Returns the header and footer of the html template as a pair.
     */
    fun load(): Pair<String, String> {
        val template = readHtmlTemplate()
        val headerEnd = template.indexOf(modelLine)
        require(headerEnd > 0) {
            "Invalid configuration cache report template!"
        }
        val header = template.substring(0, headerEnd)
        val footer = template.substring(headerEnd + modelLine.length + 1)

        val $type.implicitReceiver get() = this
        require(implicitReceiver is $type)
    """

    @Test
    @Requires(IntegTestPreconditions.NotEmbeddedExecutor::class)
    fun `pass environment`() {

        assertSucceeds(
            withBuildScript(
                """
                require(System.getProperty("myJvmSysProp") == "systemValue") { "gradleJvmOptions" }

            require(files("settings.gradle.kts").files.isNotEmpty(), { "files(paths)" })
            require(fileTree(".").contains(file("settings.gradle.kts")), { "fileTree(path)" })
            require(copySpec {} != null, { "copySpec {}" })
            require(mkdir("some").isDirectory, { "mkdir(path)" })
            require(delete("some"), { "delete(path)" })
            require(delete {} != null, { "delete {}" })

        """

            require(setExtraProperty == "extra value")

            val emptyExtraProperty: String by project
            require(emptyExtraProperty == "")

            val unsetExtraProperty: String? by project
            require(unsetExtraProperty == null)

            setProperty("setExtraProperty", "mutated")
            require(setExtraProperty == "mutated")
        }

    <!-- These packages are duplicated in ide-native from ide, don't require a package-info.java in each place -->
    <suppress checks="JavadocPackage"
              files=".*[/\\]ide-native[/\\]src[/\\]main[/\\]java[/\\]org[/\\]gradle[/\\]plugins[/\\]ide[/\\]api[/\\][^/\\]+"/>

    <!-- These packages are duplicated in platform-native from language-native, don't require a package-info.java in each place -->
    <suppress checks="JavadocPackage"

    fun set(result: BuildWorkResult) {
        require(this.result == null)
        this.result = result
    }

    override fun getType(): Class<BuildWorkResult> =
        BuildWorkResult::class.java

    override fun calculateOwnValue(consumer: ValueSupplier.ValueConsumer): ValueSupplier.Value<out BuildWorkResult> {
        require(result != null) {

        this.singletonProperty = singletonProperty
    }

    override fun <T : Any> getSingletonProperty(propertyType: Class<T>): T {
        val propertyValue = singletonProperty
        require(propertyValue != null && propertyType.isInstance(propertyValue)) {
            "A singleton property of type $propertyType has not been registered!"
        }
        return propertyValue.uncheckedCast()
    }

        for (i in 0 until nodeCount) {
            val node = readNode()
            nodesById[nodesById.size] = node
            if (node is LocalTaskNode) {
                node.prepareNode.require()
                nodesById[nodesById.size] = node.prepareNode
            }
            nodes.add(node)
        }
        // Note that using the ImmutableSet retains the original ordering of entry nodes.