/guava/guava/src/com/google/common/collect/Collections2.java
ImmutableList<E> next = ImmutableList.copyOf ( nextPermutation ) ;
@Override @CheckForNull protected List<E> computeNext() { if (nextPermutation == null) { return endOfData(); } <extra_id_0> calculateNextPermutation(); return next; } void calculateNextPermutation() { int j = findNextJ(); if (j == -1) {