public AdminNode[] getChildren() {
try {
AccessManagerClient manager = new AccessManagerClient(col.getClient());
switch ( type ) {
case RoleNode.DATABASE: {
String[] roles = manager.listRoles();
AdminNode[] list = new AdminNode[roles.length];
for ( int i = 0; i < roles.length; i++ )
list[i] = new RoleNode(this, col, roles[i], type);
return list;
}