* Initializes an empty RGroupQuery.
*
* @return a new empty RGroupQuery
*/
private IRGroupQuery newRGroupQuery(IChemObjectBuilder builder) {
IRGroupQuery rgrpQuery = new RGroupQuery(DefaultChemObjectBuilder.getInstance());
rgrpQuery.setRootStructure(builder.newInstance(IAtomContainer.class));
rgrpQuery
.setRootAttachmentPoints(new HashMap<IAtom, Map<Integer, IBond>>());
rgrpQuery.setRGroupDefinitions(new HashMap<Integer, RGroupList>());
return rgrpQuery;
}