public static OBMol addmol(OBMol source, OBMol dest)
        {
            //combines two OBMols into one molecule
            // this is designed to do the same thing as the += operator in mol.cpp, in other words this implements functionality present in openbabel, but not in the C# api
            dest.BeginModify();
            uint prevatms = dest.NumAtoms();
            uint nextatms = source.NumAtoms();

            // First, handle atoms and bonds
            foreach (OBAtom atom in source.Atoms())
            {
                atom.SetId(0); ////Need to remove ID which relates to source mol rather than this mol// But in the C++ it had a NoId thing I couldn't figure out
                dest.AddAtom(atom);
                //var foooo = dest.Atoms ();
            }
            //writeatominfotoscreen (dest);
            foreach (OBBond bond in source.Bonds())
            {
                bond.SetId(0);

                dest.AddBond((int)(bond.GetBeginAtomIdx() + prevatms), (int)(bond.GetEndAtomIdx() + prevatms),
                             (int)bond.GetBO(), (int)bond.GetFlags());
            }

            //don't really understand what they mean by residues
            //I think it's an amino acid or nucleotide so you can build up proteins and stuff?
            //don't think I'm going to use them either, but it might be useful

            foreach (OBResidue residue in source.Residues())
            {
                OBResidue newres = new OBResidue();
                dest.AddResidue(newres);

                OBResidueAtomIter ai = new OBResidueAtomIter(residue);
                //dammit why didn't they implement a residue.atoms sort of thing? I don't want to play with enumerators
                ////#define FOR_ATOMS_OF_RESIDUE(a,r) for( OBResidueAtomIter a(r); a; ++a )
                while (ai.MoveNext())
                {
                    OBAtom resatom = new OBAtom();
                    resatom = ai.Current;
                    // This is the equivalent atom in our combined molecule
                    OBAtom atom = dest.GetAtom((int)(resatom.GetIdx() + prevatms));
                    // So we add this to the last-added residue
                    // (i.e., what we just copied)
                    //[dest.NumResidues () - 1]

                    var res = dest.Residues().GetEnumerator();
                    while (!res.MoveNext())
                    {
                    }                           //move to the last residue
                    res.Current.AddAtom(atom);

                    //var item = dest.Cast<RMSRequestProcessor.RMSMedia> ().ElementAt (1);
                }


                //for(OBAtom resatom in )
            }
            dest.EndModify();

            return(dest);
        }