thanks @avillanueva I wrote a code about it
wt.org.DirectoryContextProvider contextProvider =
wt.inf.container.WTContainerHelper.service.getExchangeContainer().getContextProvider()
;
wt.org.WTGroup wgroup = wt.org.OrganizationServicesHelper.manager.getGroup(WTGName,
contextProvider);
wt.query.QuerySpec qs = new wt.query.QuerySpec(wt.org.WTGroup.class);
wt.query.SearchCondition sc = new wt.query.SearchCondition(wt.org.WTGroup.class,
wt.org.WTGroup.NAME, wt.query.SearchCondition.EQUAL, WTGName);
qs.appendWhere(sc, new int[] { 0 });
for(wt.fc.QueryResult queryResult = wt.fc.PersistenceHelper.manager.find(qs);
queryResult != null && queryResult.hasMoreElements();)
roleA=null;
wt.team.TeamHelper.service.deleteRolePrincipalMap(wt.project.Role.toRole("SUBMITTER"),
wtprincial , team );
wt.change2.ChangeIssue ci =( wt.change2.ChangeIssue)primaryBusinessObject;
wt.doc.WTDocument ci =( wt.doc.WTDocument)primaryBusinessObject;
team = wt.team.TeamHelper.service.getTeam(ci);
roleA = wt.project.Role.toRole("SUBMITTER");
team.addPrincipal(roleA, wgroup );
WTGName string is a value I assign group name to it