src/main/java/com/zandero/utils/StringUtils.java
public static String join(Set<?> items, String separator) {

		return join(items, separator, null);
	}
public static String join(Set<?> items, String separator) {

		return join(items, separator, null);
	}
public static String join ( Set < ? > items , String separator ) { return join ( items , separator , null ) ; }
Joins set of items to a single string, where items are separated
with a defined separator.

@param items     to join into string
@param separator to be used between elements
@return items joined into a single string
Joins set of items to a single string where items are separated with a defined separator .