Generate events using the external .hepmc file

Hi! I have implemented a model with 4 particles A,B,C,D, and would like to simulate the decay process A -> B + C + D, with A having some distribution. From what I have learned from 1812.06771, I need to type
import model my_model
import_events decay Adistr.hepmc
decay A > B D C
where Adistr.hepmc is a .hepmc file containing events with A. My question is the following: do I understand correctly that the .hepmc file must only contain events with A, i.e. must be of the form of

HepMC::Version 2.06.09
HepMC::IO_GenEvent-START_EVENT_LISTING
E 0 -1 -1.0000000000000000e+00 -1.0000000000000000e+00 -1.0000000000000000e+00 9999 0 667 1 2 0 1 4.1765360000000001e+04
N 1 "Weight_MERGING=0.000"
P NN A_id ...
E ...