private @Nullable T nextOrNull;

  /**
   * Creates a new iterator with the given first element, or, if {@code firstOrNull} is null,
   * creates a new empty iterator.
   */
  protected AbstractSequentialIterator(@Nullable T firstOrNull) {
    this.nextOrNull = firstOrNull;
  }

  /**
   * Returns the element that follows {@code previous}, or returns {@code null} if no elements

        "${declaringClass.baseQualifiedKotlinName}.${field.name}".let { fqn ->
            collectDescendantsOfType<KtProperty>()
                .firstOrNull { it.fqName?.asString() == fqn }
                .getSinceStatus(fallback)
        }

    private
    fun KtFile.getSince(declaringClass: CtClass, constructor: CtConstructor, fallback: String?): SinceTagStatus {

    constructorsSupplier.get().firstOrNull { c -> jvmSignature == c.signature?.toString() }?.let { predicate.match(it) } ?: false


private
fun hasFunctionAttribute(functionsSupplier: Supplier<MutableList<KmFunction>>, jvmSignature: String, predicate: AttributePredicate) =
    functionsSupplier.get().firstOrNull {
        jvmSignature == it.signature?.toString()

                    .mapNotNull {
                        it.getOrDefault(scenario.testProject, emptyList()).firstOrNull { duration ->
                            duration.scenario ==
                                scenario.scenario
                        }
                    }.firstOrNull()
                    // Fallback for new performance tests (don't use 0 to avoid division by zero)

     */
    fun sourceFileAndSourceRootFor(sourceFilePath: String): Pair<File, File> =
        sourceRoots.asSequence()
            .map { it.resolve(sourceFilePath) to it }
            .firstOrNull { it.first.isFile }
            ?: error("Source file '$sourceFilePath' not found, searched in source roots:\n  - ${sourceRoots.joinToString("\n  - ")}")

    private
    val KtFile.normalizedPath: String?

    return OkHttpDebugLogging.enable(
      "javax.net.ssl",
      object : Handler() {
        override fun publish(record: LogRecord) {
          val param = record.parameters?.firstOrNull() as? String
          debugHandler(JsseDebugMessage(record.message, param))
        }

        override fun flush() {
        }

        override fun close() {
        }
      },
    )
  }

        Jsoup.connect(buildToolsUrl)
            .get()
            .select("section:has(> h3#kts)")
            .first()
            ?.text()
            ?.lines()
            ?.firstOrNull { it.contains("buildToolsVersion = ") }
            ?.substringAfter("buildToolsVersion = ")
            ?.trim('"', ' ')
            ?: error("Couldn't find buildToolsVersion on $buildToolsUrl")

            error("Can't find the contributors section in the release notes $releaseNotes.")
        }

        val contributorSectionEndIndex = (contributorSectionBeginIndex until releaseNotesLines.size).firstOrNull {
            val line = releaseNotesLines[it].trim()
            line.isNotEmpty() && !line.startsWith("[")
        } ?: error("Can't find the contributors section end in the release notes $releaseNotes.")

  /** Returns the remote peer's principle, or null if that peer is anonymous. */
  @get:JvmName("peerPrincipal")
  val peerPrincipal: Principal?
    get() = (peerCertificates.firstOrNull() as? X509Certificate)?.subjectX500Principal

  @JvmName("-deprecated_peerPrincipal")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "peerPrincipal"),

    val name = this.name
    return incoming.files.elements.map {
        require(it.size <= 1) {
            "Expected at most one file in configuration '$name' but found: $it"
        }
        it.firstOrNull()?.asFile
    }
}

fun NamedDomainObjectProvider<Configuration>.getSingleFileProvider(): Provider<File> {
    return this.flatMap { configuration ->
        configuration.getSingleFileProvider()
    }