%matplotlib in the source notebook causes error

It's really wierd that when the source notebook has the magic cell funcction `%matplotlib inline` statement,
the `from ipynb.fs.defs.one_eda import guess_age` throws an error citing the same.

Start by reproducing the failure with a source notebook containing the `%matplotlib inline` magic and the `from ipynb.fs.defs.one_eda import guess_age` import. Use the resulting traceback to locate the importer path involved; done means the import succeeds without the magic cell causing an error.

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