prop_command :: I.Command -> Bool
prop_command c = 
  Just c == maybeResult (feed (parse I.command (B.pack (show c))) B.empty)
prop_command :: I.Command -> Bool
prop_command c = 
  Just c == maybeResult (feed (parse I.command (B.pack (show c))) B.empty)
prop_command c = 
  Just c == maybeResult (feed (parse I.command (B.pack (show c))) B.empty)