def add_edge_features(self,seq,pos,y,y_prev,edge_idx):
        #print "Adding edge feature for pos:%i y:%i y_prev%i seq_len:%i"%(pos,y,y_prev,len(seq.x))
        y_name = self.dataset.int_to_pos[y]
        y_prev_name = self.dataset.int_to_pos[y_prev]
        if(pos == len(seq.x)-1):
            feat = (y_prev_name,y_name)%"last_prev_tag:%s::%s"
        else: 
           feat = "prev_tag:%s::%s"%(y_prev_name,y_name)
        nr_feat = self.add_feature(feat)
        if(nr_feat != -1):
            edge_idx.append(nr_feat)
        return edge_idx

    #f(t,y_t,y_(t-1),X)
    ##Speed up of code
dataset/ETHPy150Open LxMLS/lxmls-toolkit/lxmls/sequences/bak/postag_features.py/ExtendedFeatures.add_edge_features/swapped operands of `%`