get (HsTyVar tv) = unitNameSet tv
get (HsSpliceTy {}) = emptyNameSet -- Type splices mention no type variables
get (HsSpliceTyOut {}) = emptyNameSet -- Ditto
get (HsTyVar tv) = unitNameSet tv
get (HsSpliceTy {}) = emptyNameSet -- Type splices mention no type variables
get (HsSpliceTyOut {}) = emptyNameSet -- Ditto