A few refactorizations and transfer-learning notebook

[blythed]

Description

Created a notebook for the transfer learning use case.

Checklist

• Change or addition is covered by unit and/or integration tests. If bugfix, there should be at least one test that fails pre-PR and passes after.
• Classes and functions substantially affected by this PR have sphinx format docstrings added or updated.
• If your changes introduce modifications to functionality, behavior, or usage of the project, please ensure that the documentation is updated accordingly.

[rec]

In a more leisurely day I'd strongly suggest splitting this up, but ah well.

The git stuff was taken directly from another project, so it's not like it's gone!