@enum Transaction create=1 modify=2 delete=3

struct Action{T}
    # Short names since they are serialized a lot
    a::Transaction
    o::T
end

MsgPack.msgpack_type(::Type{Action{T}}) where T = MsgPack.StructType()
MsgPack.msgpack_type(::Type{Transaction}) = MsgPack.IntegerType()
Base.isless(r::Transaction, i::Int64) = isless(Int(r), i)
Base.convert(::Type{Transaction}, i::Integer) = Transaction(i)