/**
   * Method getParticipant.
   *
   * @param aId - String
   * @return R4EParticipant
   */
  protected R4EParticipant getParticipant(String aId) {
    // First check if the participant already exist in the participant list
    for (R4EParticipant tmpPart : fParticipants) {
      if (aId.equalsIgnoreCase(tmpPart.getId())) {
        return null;
      }
    }
    final R4EParticipant participant = RModelFactory.eINSTANCE.createR4EParticipant();
    if (R4EUIModelController.isUserQueryAvailable()) {
      final IQueryUser query = new QueryUserFactory().getInstance();
      try {
        final List<IUserInfo> users = query.searchByUserId(aId);

        // Fill info with first user returned
        for (IUserInfo user : users) {
          if (user.getUserId().toLowerCase().equals(aId)) {
            participant.setId(user.getUserId().toLowerCase());
            participant.setEmail(user.getEmail());
            fParticipantsDetailsValues.add(UIUtils.buildUserDetailsString(user));
            return participant;
          }
        }
      } catch (NamingException e) {
        R4EUIPlugin.Ftracer.traceError("Exception: " + e.toString() + " (" + e.getMessage() + ")");
        R4EUIPlugin.getDefault().logError("Exception: " + e.toString(), e);
      } catch (IOException e) {
        R4EUIPlugin.getDefault().logWarning("Exception: " + e.toString(), e);
      }
    }
    participant.setId(aId);
    fParticipantsDetailsValues.add("");
    return participant;
  }
  /**
   * Method addUserToParticipantList.
   *
   * @param aUserInfo - IUserInfo
   */
  private void addUserToParticipantList(IUserInfo aUserInfo) {

    // First check if the participant already exist in the participant list
    for (R4EParticipant tmpPart : fParticipants) {
      if (aUserInfo.getUserId().equalsIgnoreCase(tmpPart.getId())) {
        return;
      }
    }

    // Add User to List
    final R4EParticipant participant = RModelFactory.eINSTANCE.createR4EParticipant();
    participant.setId(aUserInfo.getUserId());
    participant.setEmail(aUserInfo.getEmail());
    fParticipantsDetailsValues.add(UIUtils.buildUserDetailsString(aUserInfo));
    fParticipants.add(participant);

    updateComponents(participant);
  }