code: public Structure getStructureForCathDomain(StructureName structureName, CathDatabase cathInstall) throws IOException, StructureException {
  
  		CathDomain cathDomain = cathInstall.getDomainByCathId(structureName.getIdentifier());
  
  		Structure s = getStructureForPdbId(cathDomain.getIdentifier());
  		Structure n = cathDomain.reduce(s);
  
  		// add the ligands of the chain...
  
  		Chain newChain = n.getPolyChainByPDB(structureName.getChainId());
  		List<Chain> origChains = s.getNonPolyChainsByPDB(structureName.getChainId());
  		for ( Chain origChain : origChains) {
  			List<Group> ligands = origChain.getAtomGroups();
  
  			for (Group g : ligands) {
  				if (!newChain.getAtomGroups().contains(g)) {
  					newChain.addGroup(g);
  				}
  			}
  		}
  
  		return n;
  	}
docs: Returns a {@link Structure} corresponding to the CATH identifier supplied in {@code structureName}, using the specified {@link CathDatabase}.