Store gen_id in the TruthParticle object when it's provided in the la…

…rcv.Particle one

analysis/classes/TruthParticle.py

@@ -114,6 +114,10 @@ def register_larcv_particle(self, particle):
         for k in scalar_keys:
             val = getattr(particle, k)()
             setattr(self, k, val)
+
+        # TODO: Move this to main list once this is in every LArCV file
+        if hasattr(particle, 'gen_id'):
+            setattr(self, 'gen_id', particle.gen_id())
 
         # Exception for particle_id
         self.truth_id = particle.id()
@@ -178,6 +182,10 @@ def load_larcv_attributes(self, particle_dict):
                 attr = attr.decode()
             setattr(self, attr_name, attr)
 
+        # TODO: Move this to main list once this is in every LArCV file
+        if 'gen_id' in particle_dict:
+            setattr(self, 'gen_id', particle_dict['gen_id'])
+
     def merge(self, particle):
         '''
         Merge another particle object into this one