[Feature] Extract primers from modules that contain RNNs

[albertbou92]

Description

This PR adds a utils method to address #1771

Motivation and Context

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You can use the syntax close #15213 if this solves the issue #15213

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• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of examples)

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[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/rl/2127

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❌ 4 New Failures, 2 Unrelated Failures

As of commit f48eb0c with merge base 68101b0 ():

NEW FAILURES - The following jobs have failed:

• Continuous Benchmark (PR) / CPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Continuous Benchmark (PR) / GPU Pytest benchmark (gh)
  Workflow failed! Resource not accessible by integration
• Habitat Tests on Linux / tests (3.9, 12.1) / linux-job (gh)
  RuntimeError: Command docker exec -t b832a3ad5e195d20332203e6dd6e77182da0b5e1f7937fb4ffd7a621f3772afa /exec failed with exit code 139
• Unit-tests on Linux / tests-optdeps (3.10, 12.1) / linux-job (gh)
  RuntimeError: Command docker exec -t aa0c8e18e70815d0d3b1c66c069128fb9035344b93d66c78ab5953add0ce9692 /exec failed with exit code 1

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Unit-tests on Linux / tests-olddeps (3.8, 11.6) / linux-job (gh) (trunk failure)
  test/test_rb.py::TestRBMultidim::test_rb_multidim_collector[env_device0-transform1-sampler_cls4-rbtype1-LazyTensorStorage-TensorDictRoundRobinWriter]
• Unit-tests on Windows / unittests-cpu / windows-job (gh) (trunk failure)
  test/test_collector.py::TestLibThreading::test_auto_num_threads

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[albertbou92]

pre-commit reformatted this

[vmoens]

Thanks so much for this!

Here is what is missing:

• Add the function to the doc
• Provide an example.
• Add test for the feature.
• Cross reference this class in tensordict primer and rnns.

[vmoens]

Can we write a couple of tests for this feature? Thanks!

[albertbou92]

I was about to push them haha

[vmoens]

LGTM!