deriveXPubKey :: XPrvKey -> XPubKey
deriveXPubKey (XPrvKey d p i c k) = XPubKey d p i c (derivePubKey k)
deriveXPubKey :: XPrvKey -> XPubKey
deriveXPubKey (XPrvKey d p i c k) = XPubKey d p i c (derivePubKey k)
deriveXPubKey (XPrvKey d p i c k) = XPubKey d p i c (derivePubKey k)