Some species states are not converted from celldesigner sbml to sbgn-ml

When converting neuron_cd.xml to SBGN-ML some species modifications, such as phosphorylation, are retained, but some do not. For example, DRD1 (left border of the compartment) translated well, but HTT (right upper corner) does not. The issue might be, that it is not transferred when it is more complicated modification (in case of HTT "mutated polyQ"). Based on the sbgn-ml doc, the state is simple string, so it should be possible to encode arbitrary modifiations.