Error when running the CenterNet notebook on Colab

[Agh404180]

I'm trying to run the CenterNet notebook on Google Colab, but I’m facing two issues:

1. PyTorch Version Issue:
   When running the notebook, I get the following error:

Looking in links: https://download.pytorch.org/whl/cu101/torch_stable.html
ERROR: Could not find a version that satisfies the requirement torch==1.4 (from versions: 1.13.0, 1.13.1, 2.0.0, 2.0.1, 2.1.0, 2.1.1, 2.1.2, 2.2.0, 2.2.1, 2.2.2, 2.3.0, 2.3.1, 2.4.0, 2.4.1, 2.5.0, 2.5.1, 2.6.0)
ERROR: No matching distribution found for torch==1.4
I am unable to install torch 1.4 because it is no longer available in the package index.

2. ModuleNotFoundError for _ext:
   Additionally, I’m seeing this error when attempting to import DCNv2:

ModuleNotFoundError: No module named '_ext'