code: public void enter(Permutation g) {
          int deg = size;
          int i = test(g);
          if (i == deg) {
              return;
          } else {
              permutations[i][g.get(base.get(i))] = new Permutation(g);
          }
  
          for (int j = 0; j <= i; j++) {
              for (int a = 0; a < deg; a++) {
                  Permutation h = permutations[j][a];
                  if (h != null) {
                      Permutation f = g.multiply(h);
                      enter(f);
                  }
              }
          }
      }
docs: Enter the permutation g into this group.
  
  @param g a permutation to add to the group