-- | Add a command to a subparser option.
command :: String -> ParserInfo a -> Mod CommandFields a
command cmd pinfo = fieldMod $ \p ->
  p { cmdCommands = (cmd, pinfo) : cmdCommands p }
command :: String -> ParserInfo a -> Mod CommandFields a
command cmd pinfo = fieldMod $ \p ->
  p { cmdCommands = (cmd, pinfo) : cmdCommands p }
command cmd pinfo = fieldMod $ \p ->
  p { cmdCommands = (cmd, pinfo) : cmdCommands p }