/**
   * Gets the Interaction Participant List.
   *
   * @param interaction Interaction object.
   * @return Castor Participant List.
   */
  private InteractionElementType.ParticipantList getParticipantList(
      org.cytoscape.coreplugin.psi_mi.model.Interaction interaction) {
    InteractionElementType.ParticipantList participantList =
        new InteractionElementType.ParticipantList();

    List interactors = interaction.getInteractors();

    for (int i = 0; i < interactors.size(); i++) {
      Interactor interactor = (Interactor) interactors.get(i);
      String name = interactor.getName();
      ParticipantType participant1 = createParticipant(name);
      participantList.getParticipant().add(participant1);
    }

    return participantList;
  }
  /**
   * Gets a complete list of NonRedundant Proteins.
   *
   * @return HashMap of NonRedundant Proteins.
   */
  private HashMap getNonRedundantInteractors() {
    HashMap interactorMap = new HashMap();

    for (int i = 0; i < interactions.size(); i++) {
      org.cytoscape.coreplugin.psi_mi.model.Interaction interaction =
          (org.cytoscape.coreplugin.psi_mi.model.Interaction) interactions.get(i);
      List interactors = interaction.getInteractors();

      for (int j = 0; j < interactors.size(); j++) {
        Interactor interactor = (Interactor) interactors.get(j);
        addToHashMap(interactor, interactorMap);
      }
    }

    return interactorMap;
  }