public void addNeuronGroup(NeuronGroup group){
  numMembers+=group.size();
  neuronGroupList.add(group);
  group.setParentGroup(this);
}

public void addNeuronGroup ( NeuronGroup group ) { numMembers += group . size ( ) ; neuronGroupList . add ( group ) ; group . setParentGroup ( this ) ; }
add a neuron group .
