Check Signature

[bestickley]

How can I check a PDFSignature field to see if it's been signed/filled? I know in the docs it says:

PDFSignature fields are digital signatures. pdf-lib does not currently provide any specialized APIs for creating digital signatures or reading the contents of existing digital signatures.

However, I'm not trying to read the contents per say, I'm just trying to check (binary) if it has been signed.