how to change the num_instances when i detect the image?

## 📚 Documentation Issue

I predict the image show:detected 100 instances in 0.69s,and i print the predictor:Instances(num_instances=100, image_height=1080,
my weight only have 2 class, i want to change the num_instances ,please tell me how to change

No file, test, or entry point is named. Start by checking Detectron2's predictor documentation and the meaning of Instances(num_instances=100), then determine whether the report concerns limiting detections or an incorrect class configuration. Done means documenting the relevant setting or explaining why num_instances is independent of the number of classes.

Written by the indexing model from the issue text.