[Cbc] How to add cuts?

[不入角蜗牛]

Hello.
I try to use the class CbcEventHandler to add cuts to solve my problem, but it doesn't work.
for example :
min: x2
s.t. x0 + x1 >= 1;
      x1 + x2 >= 1;
x0,x1,x2 in {0,1}
Add the question normally. I get x0 = 1, x1 = 1 and x2 = 0. But when I try to add a cut x0 = 0 with codes:
<\code
        auto refSolver = model->referenceSolver(); 
        CoinPackedVector solution_cut;
        solution_cut.setVector(len, &cols[cols.size()-len], &values[values.size()-len]);
        refSolver->addRow(solution_cut, rhs_lower.back(), rhs_upper.back());
        model->resetToReferenceSolver();
code\> 
But failed. I save the model as mps file and it can be read as:
 TITLE BLANK;
 [ OBJROW] MIN =  C0000002;
 [ R0000000]  C0000000 +  C0000001 >= 1;
 [ R0000001]  C0000001 +  C0000002 >= 1;
 [ R0000002]  C0000000 = 0;
 @BND( 0, C0000000, 0); @BND( 0, C0000001, 0);
 @BND( 0, C0000002, 0);
Thanks.
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