public NeuronPair getNeuronPair(TYPE n1,TYPE n2){
        NeuronPair np = null;
        for(NeuronPair pair : pairs.keySet()){
            if((pair.getN1()==n1  && pair.getN2()==n2) || (pair.getN1()==n2 && pair.getN2()==n1))
                np = pair;
        }
        return np;
    }