Partition { public boolean inOrder() { SortedSet<Integer> prev = null; for (SortedSet<Integer> cell : cells) { if (prev == null) { prev = cell; } else { int first = cell.first(); int last = cell.last(); if (first > prev.first() && last > prev.last()) { prev = cell; } else { return false; } } } return true; } Partition();  Partition(Partition other);  Partition(int[][] cellData); static Partition unit(int size); @Override boolean equals(Object o); @Override int hashCode(); int size(); int numberOfElements(); boolean isDiscrete(); Permutation toPermutation(); boolean inOrder(); int getFirstInCell(int cellIndex); SortedSet<Integer> getCell(int cellIndex); Partition splitBefore(int cellIndex, int splitElement); Partition splitAfter(int cellIndex, int splitElement); Permutation setAsPermutation(int upTo); boolean isDiscreteCell(int cellIndex); int getIndexOfFirstNonDiscreteCell(); void addSingletonCell(int element); void removeCell(int index); void addCell(int... elements); void addCell(Collection<Integer> elements); void addToCell(int index, int element); void insertCell(int index, SortedSet<Integer> cell); SortedSet<Integer> copyBlock(int cellIndex); void order(); boolean inSameCell(int elementI, int elementJ); @Override String toString(); static Partition fromString(String strForm);  }
@Test public void inOrderTest() { int[][] cellData = new int[][]{{0, 1}, {2, 3, 4}, {5, 6}}; Partition p = new Partition(cellData); Assert.assertTrue(p.inOrder()); }