About the physics process of chem6

dear everyone:

i try to study the chem6 from the examples. Shin et al., have developed the “ELastic Scattering
of Electrons and Positrons by neutral Atoms” (ELSEPA) model into Geant4-DNA 。but i saw the code
in this example.
RegisterConstructor(“G4EmDNAPhysics_option2”);
RegisterConstructor(“G4EmDNAChemistry_option3”);

G4EmDNAPhysics_option2 does not include the G4DNAELSEPAElasticModel.
i do not know how to add the G4DNAELSEPAElasticModel in the physics process.