```
/home/tej/code/gbuella_paddle/paddle/fluid/framework/ir/seqpool_concat_fuse_pass_tester.cc:167:40: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
    std::string prefix = "seqpool_op_" + i;
                         ~~~~~~~~~~~~~~^~~
/home/tej/code/gbuella_paddle/paddle/fluid/framework/ir/seqpool_concat_fuse_pass_tester.cc:167:40: note: use array indexing to silence this warning
    std::string prefix = "seqpool_op_" + i;
                                       ^
                         &             [  ]
1 error generated.
```

test=develop