Generating more than 1 primary particle in RestG4

RestG4
1

I have been trying to generate more than one particle in each event. I have tried adding two neutron sources definitions inside the generator. As far as I have read, that will generate the two paticles in the same point, but thats not a problem for the tests that I want to do. Nevertheless, I get the following error:

TRestGeant4Event: Number of particles on primary vertex does not match number of sources for event ID: 0

That error is defined in the SimulationManager class of restG4:

if ((event->GetPrimaryVertex()->GetNumberOfParticle() !=
         fEvent->GetGeant4Metadata()->GetNumberOfSources()) &&
        (int(fEvent->GetNumberOfPrimaries()) != fEvent->GetGeant4Metadata()->GetNumberOfSources())) {
        cout << "TRestGeant4Event: Number of particles on primary vertex does not match number of sources "
                "for event ID: "
             << fEvent->GetID() << endl;
        exit(1);
    }

So I dont know if there is a way to set the number of primaries to be generated from the RML file or if we have to modify the libraries files.

I attach the RML file that I use for the simulation:
Sim_2mult_test.rml (3.7 KB)

The code part of the generator is the following:

<generator type="point" position="(0,0,6)" units="m" >
    
      <source particle="neutron" fullChain="off">
      	<energy type="TH1D" file="Spectra/Gordon.root" name="Neutron_flux"/>
      	<angular type="flux" direction="(0,0,-1)" />
      </source>
      
      <source particle="neutron" fullChain="off">
      	<energy type="TH1D" file="Spectra/Gordon.root" name="Neutron_flux"/>
      	<angular type="flux" direction="(0,0,-1)" />
      </source>
      
    </generator>