public Collection<Group> search(String propName, String propValue) {
        Collection<String> groupsWithProps = provider.search(propName, propValue);
        return new GroupCollection(groupsWithProps);
    }
Returns an unmodifiable Collection of all groups in the system that
match given propValue for the specified propName.

@param propName the property name to search for
@param propValue the property value to search for
@return an unmodifiable Collection of all matching groups.
xmppserver/src/main/java/org/jivesoftware/openfire/group/GroupManager.java