if a.hpaSelectors.SelectorExists(hpaKey) {
		// Update HPA selector only if the HPA was registered in enqueueHPA.
		a.hpaSelectors.PutSelector(hpaKey, parsedSelector)
	}
	a.hpaSelectorsMux.Unlock()

	pods, err := a.podLister.Pods(hpa.Namespace).List(parsedSelector)
	if err != nil {
		return nil, err
	}

	selectingHpas := a.hpasControllingPodsUnderSelector(pods)
	if len(selectingHpas) > 1 {

		selector := action.(core.ListAction).GetListRestrictions().Labels
		parsedSelector := strings.Split(selector.String(), "=")
		if len(parsedSelector) > 1 {
			labelSet[parsedSelector[0]] = parsedSelector[1]
			podNamePrefix = parsedSelector[1]
		}

		podMetric := metricsapi.PodMetrics{
			ObjectMeta: metav1.ObjectMeta{

//  5. A requirement with just !KEY requires that the KEY not exist.
func Parse(selector string, opts ...field.PathOption) (Selector, error) {
	parsedSelector, err := parse(selector, field.ToPath(opts...))
	if err == nil {
		return parsedSelector, nil
	}
	return nil, err
}

// parse parses the string representation of the selector and returns the internalSelector struct.

    }

    def "creates sub version selector"() {
        expect:
        matcher.parseSelector(selector) instanceof SubVersionSelector

        where:
        selector << [
            "1+",
            "1.2.3+"
        ]
    }

    def "creates latest version selector"() {
        expect:
        matcher.parseSelector(selector) instanceof LatestVersionSelector

        where:
        selector << [

        def selectedComponentResult = Mock(ComponentSelectionContext)

        when:
        chooser.selectNewestMatchingComponent([c, d, a, b], selectedComponentResult, versionSelectorScheme.parseSelector("1.+"), versionSelectorScheme.parseSelector("1.3"), consumerAttributes)

        then:
        _ * componentSelectionRules.rules >> []
        1 * selectedComponentResult.getContentFilter() >> null

        isStrict = !strictVersion.isEmpty();
        String version = isStrict ? strictVersion : requiredVersion;
        this.requiredVersionSelector = scheme.parseSelector(version);
        this.preferredVersionSelector = preferredVersion.isEmpty() ? null : scheme.parseSelector(preferredVersion);

        if (isStrict) {
            VersionSelector rejectionForStrict = getRejectionForStrict(version, scheme);

    def mapper = new MavenVersionSelectorScheme(defaultMatcher)

    def "translates to maven syntax"() {
        given:
        def selector = defaultMatcher.parseSelector(input)

        expect:
        mapper.renderSelector(selector) == output

        where:
        input                | output
        "]2,3]"              | "(2,3]"
        "[2,3["              | "[2,3)"

        this.delegate = delegate;
    }

    @Override
    public VersionSelector parseSelector(String selectorString) {
        VersionSelector versionSelector = cachedSelectors.get(selectorString);
        if (versionSelector == null) {
            versionSelector = delegate.parseSelector(selectorString);
            cachedSelectors.put(selectorString, versionSelector);
        }
        return versionSelector;

}

func TestDeterministicParse(t *testing.T) {
	s1, err := ParseSelector("x=a,a=x")
	s2, err2 := ParseSelector("a=x,x=a")
	if err != nil || err2 != nil {
		t.Errorf("Unexpected parse error")
	}
	if s1.String() != s2.String() {
		t.Errorf("Non-deterministic parse")
	}
}

func expectMatch(t *testing.T, selector string, ls Set) {
	lq, err := ParseSelector(selector)
	if err != nil {

	return Selector{
		present: NewSet(present...),
		absent:  NewSet(absent...),
	}
}

var userLabelRegex = regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9_]*(\.[a-zA-Z0-9_]+)*$`)

// ParseSelector parses and returns a new instance of Selector.
func ParseSelector(s string) (Selector, error) {
	var present, absent []Instance

	parts := strings.Split(s, ",")
	for _, p := range parts {
		if len(p) == 0 {
			continue
		}