+ // TODO: tighten PDB dbrefs
+ // formally imply Jalview has actually downloaded and
+ // parsed the pdb file. That means there should be a cached file
+ // handle on the PDBEntry, and a real mapping between sequence and
+ // extracted sequence from PDB file
+ PDBEntry pdbentry = getPDBEntry(ref.getAccessionId());
+ if (pdbentry != null && pdbentry.getFile() != null)