Optional [ list [ Optional [ Data Structures ] ] ]

[buggybuck]

Hi there!

I'm trying to deserialize this twisted little line here [1]:

message_data: Optional[list[Optional[SignatureRequestSourceData]]]

Does it mean that if there is a list (1st Optional) then the list will always contain at least one element? Either 0x00 if the SignatureRequestSourceData item isn't present or 0x01 plus the SignatureRequestSourceData item?

Is the inner Optional really necessary? I have the impression that the (non-)existence of the item is already established by the serialized length of the list, and deserializing the inner Optional feels a little futile. Although I enjoyed the little mind twist :) ;)

Kind regards

[1] https://github.com/Chia-Network/chia-blockchain/blob/main/chia/protocols/harvester_protocol.py#L95