}

    public GradleVersionSpec() {
        this.lowestTestedVersion = getLowestTestedVersion();
    }

    public GradleVersionSpec(String lowestTestedVersion) {
        this.lowestTestedVersion = GradleVersion.version(lowestTestedVersion);
    }

    public Spec<GradleVersion> toSpec(String constraint) {
        String trimmed = constraint.trim();
        if (trimmed.equals("current")) {

            this.setSystemPropertiesOfTestJVM("latest")
            this.systemProperties["org.gradle.integtest.crossVersion"] = "true"
            this.systemProperties["org.gradle.integtest.crossVersion.lowestTestedVersion"] = releasedVersions?.lowestTestedVersion?.version

            // We should always be using JUnitPlatform at this point, so don't call useJUnitPlatform(), else this will

    val allTestedVersions: List<GradleVersion>

    val mainTestedVersions: List<GradleVersion>
    val lowestInterestingVersion: GradleVersion
    val lowestTestedVersion: GradleVersion

    init {
        lowestTestedVersion = GradleVersion.version("3.0")
        lowestInterestingVersion = GradleVersion.version("0.8")

        val releasedVersions = releasedVersionsFile.asFile.reader().use {