code: public boolean contains(IAtom atom) {
          for (int i = 0; i < atomCount; i++) {
              if (atoms[i].equals(atom)) {
                  return true;
              }
          }
          return false;
      }
docs: Returns true if the given atom participates in this Association.
  
  @param   atom  The atom to be tested if it participates in this Association
  @return     true if the atom participates in this Association