policyFileBackend = new SimpleFileProviderBackend(getAuthzConf(),
getAuthzConf().get(AuthzConfVars.AUTHZ_PROVIDER_RESOURCE.getVar()));
ProviderBackendContext context = new ProviderBackendContext();
context.setAllowPerDatabase(true);
policyFileBackend.initialize(context);
client = new SentryPolicyServiceClient(getAuthzConf());
Set<String> roles = new HashSet<String>();
for (TSentryRole sentryRole : client.listRoles(requestorUserName)) {
roles.add(sentryRole.getRoleName());
}