code: public int[] getEquivalenceClassesSizeVector() {
          List equivalenceClasses = cycleBasis().equivalenceClasses();
          int[] result = new int[equivalenceClasses.size()];
          for (int i = 0; i < equivalenceClasses.size(); i++) {
              result[i] = ((Collection) equivalenceClasses.get(i)).size();
          }
          return result;
      }
docs: Returns a vector containing the size of the "interchangeability" equivalence classes.
  The vector is uniquely defined for any SSSR of a molecule.
  
  @return An <code>int[]</code> containing the size of the equivalence classes in a SSSR