a-foundation/src/main/java/com/ajjpj/afoundation/collection/ACollectionHelper.java
public static String mkString(Iterable<?> iterable, String prefix, String separator, String suffix) {
        final StringBuilder result = new StringBuilder(prefix);

        boolean first = true;
        for(Object o: iterable) {
            if(first) {
                first = false;
            }
            else {
                result.append(separator);
            }
            result.append(o);
        }

        result.append(suffix);
        return result.toString ();
    }
public static String mkString(Iterable<?> iterable, String prefix, String separator, String suffix) {
        final StringBuilder result = new StringBuilder(prefix);

        boolean first = true;
        for(Object o: iterable) {
            if(first) {
                first = false;
            }
            else {
                result.append(separator);
            }
            result.append(o);
        }

        result.append(suffix);
        return result.toString ();
    }
Returns a string representation of a collection, separating elements with a <code>separator</code> and putting
<code>prefix</code> before the first and a <code>suffix</code> after the last element.