Leave NonEmptySet as-is at insertion of item that's already in it
Leave NonEmptySet as-is at insertion of item that's already in it

input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,input-output-hk/cardano-sl,input-output-hk/cardano-sl,input-output-hk/pos-haskell-prototype,serokell/tw-rework-sketch,input-output-hk/cardano-sl