func NewSingleton[T any]() *Singleton[T] {
	return &Singleton[T]{set: make(chan struct{}), v: nil}
}

// Get will return the singleton value.
func (s *Singleton[T]) Get() *T {
	<-s.set
	return s.v
}

// GetNonBlocking will return the singleton value or nil if not set yet.
func (s *Singleton[T]) GetNonBlocking() *T {
	select {
	case <-s.set:
		return s.v
	default:
		return nil
	}
}

        String value = joiner.toString();
        if (value.isEmpty()) {
            return new String[0];
        }
        return new String[] {option, value};
    }

    /**
     * {@return a string representation of this path type for debugging purposes}.
     */
    @Override
    public String toString() {
        return "PathType[" + id() + ']';
    }

    /**

    public static class MyBean {

        /**
         * @return String
         */
        public String getAaa() {
            return null;
        }

        /**
         * @param a
         * @return String
         */
        public String getBbb(final Object a) {
            return null;
        }

        /**
         * @return boolean
         */
        public boolean isCCC() {

                directoryCache.remove(directoryPath);
                return null;
            }
        }

        return entry;
    }

    /**
     * Check if directory listing can be cached
     *
     * @param directoryPath directory path
     * @return true if caching is allowed
     */
    public boolean canCacheDirectoryListing(String directoryPath) {

    public DuplicateHostDbm asDBMeta() {
        return DuplicateHostDbm.getInstance();
    }

    @Override
    public String asTableDbName() {
        return "duplicate_host";
    }

    @Override
    public boolean hasSpecifiedColumn() {
        return _specification != null;
    }

    @Override
    public ConditionQuery localCQ() {
        return doGetConditionQuery();
    }

    public RelatedQueryDbm asDBMeta() {
        return RelatedQueryDbm.getInstance();
    }

    @Override
    public String asTableDbName() {
        return "related_query";
    }

    @Override
    public boolean hasSpecifiedColumn() {
        return _specification != null;
    }

    @Override
    public ConditionQuery localCQ() {
        return doGetConditionQuery();
    }

),d=a.getElementsByTagName("head")[0]||a.documentElement;return c.innerHTML="x<style>"+b+"</style>",d.insertBefore(c.lastChild,d.firstChild)}function d(){var a=t.elements;return"string"==typeof a?a.split(" "):a}function e(a,b){var c=t.elements;"string"!=typeof c&&(c=c.join(" ")),"string"!=typeof a&&(a=a.join(" ")),t.elements=c+" "+a,j(b)}function f(a){var b=s[a[q]];return b||(b={},r++,a[q]=r,s[r]=b),b}function g(a,c,d){if(c||(c=b),l)return c.createElement(a);d||(d=f(c));var e;return e=d.cache[a]...

     * @return the list of popular words
     */
    public List<String> getWords() {
        return words;
    }

    /**
     * Returns the number of popular words.
     *
     * @return the number of popular words
     */
    public int getNum() {
        return num;
    }

    /**
     * Returns the total number of words.
     *
     * @return the total number of words
     */

	switch mt {
	case CounterMT:
		return "counter"
	case GaugeMT:
		return "gauge"
	case HistogramMT:
		return "histogram"
	default:
		return "*unknown*"
	}
}

func (mt MetricType) toProm() prometheus.ValueType {
	switch mt {
	case CounterMT:
		return prometheus.CounterValue
	case GaugeMT:
		return prometheus.GaugeValue
	case HistogramMT:
		return prometheus.CounterValue
	default:

    }

    /**
     * Get remote memory key
     *
     * @return remote memory key (token)
     */
    public int getRemoteKey() {
        return transform.getToken();
    }

    /**
     * Get remote memory address
     *
     * @return remote memory address (offset)
     */
    public long getAddress() {
        return transform.getOffset();
    }

    /**
     * Get length of memory region