public static RecurrenceIterator join ( RecurrenceIterator a , RecurrenceIterator ... b ) { List < RecurrenceIterator > incl = new ArrayList < RecurrenceIterator > ( ) ; incl . add ( a ) ; incl . addAll ( Arrays . asList ( b ) ) ; return new CompoundIteratorImpl ( incl , Collections . < RecurrenceIterator > emptyList ( ) ) ; }
a recurrence iterator that returns the union of the given recurrence iterators .