Permutation { public void set(int index, int value) { this.values[index] = value; } Permutation(int size);  Permutation(int... values);  Permutation(Permutation other); @Override boolean equals(Object other); @Override int hashCode(); boolean isIdentity(); int size(); int get(int index); int[] getValues(); int firstIndexOfDifference(Permutation other); List<Integer> getOrbit(int element); void set(int index, int value); void setTo(Permutation other); Permutation multiply(Permutation other); Permutation invert(); String toCycleString(); @Override String toString();  }
@Test public void setTest() { Permutation p = new Permutation(1, 0); p.set(0, 0); p.set(1, 1); Assert.assertEquals(0, p.get(0)); Assert.assertEquals(1, p.get(1)); }