Net.Ethernet.Packet not instance of typeclass Unparse

Net.Ethernet.Packet is not an instance of typeclass Unparse, but Net.Ethernet contains a function called unparse which presumably does the work of doUnparse on a Net.Ethernet.Packet. Presumably in the background an instance of typeclass Unparse is lurking!

Writing out the instance would uniformize the interface here, and make doUnparse the default interface for unparsing. At the moment, one can't doUnparse a Net.Ethernet.Packet object.