Partition { public SortedSet<Integer> getCell(int cellIndex) { return this.cells.get(cellIndex); } 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 getCellTest() { int[][] cellData = new int[][]{{0, 1}, {2, 3, 4}, {5, 6}}; Partition p = new Partition(cellData); for (int i = 0; i < cellData.length; i++) { Integer[] cell = p.getCell(i).toArray(new Integer[]{}); Assert.assertEquals(cellData[i].length, cell.length); for (int j = 0; j < cell.length; j++) { Assert.assertEquals(cellData[i][j], (int) cell[j]); } } }