prop_prefix :: I.Prefix -> Bool
prop_prefix c = 
  Just c == maybeResult (feed (parse (char8 ':' *> I.prefix) (I.prefixToByteString c `B.append` " ")) B.empty)
prop_prefix :: I.Prefix -> Bool
prop_prefix c = 
  Just c == maybeResult (feed (parse (char8 ':' *> I.prefix) (I.prefixToByteString c `B.append` " ")) B.empty)
prop_prefix c = 
  Just c == maybeResult (feed (parse (char8 ':' *> I.prefix) (I.prefixToByteString c `B.append` " ")) B.empty)