NameError: name 'predictor' is not defined

[zhanglu11]

I have installed the package and can import it, and I can run the code deepsort.demo(), but when running：
test_file = 'D:/rwork/allcount.csv'
predictor.predict(test_file, save_path='results')
it reports an error：
Traceback (most recent call last):
File "", line 1, in
NameError: name 'predictor' is not defined
Could anyone help me with this error？