Optional
_idA unique document ID (Mongo DB ObjectID)
Optional
contentThe content of the fetch document. Note that we store balances in BALANCES_DB and not here to avoid double storage.
The type of content fetched. This is used for querying purposes
The time the document was fetched
The block the document was fetched
True if the document is permanent (i.e. fetched from a permanent URI like IPFS)
A unique stringified document ID