anchor.diff:  read(_, _) ->
       {error, badarg}.
   
  --spec read_line(File :: io_device()) ->
  +-spec read_line(File :: io_device() | atom()) ->
   	'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
   
   read_line(File) when (is_pid(File) orelse is_atom(File)) ->
  
positive.code: pread(_, _, _) ->
      {error, badarg}.
  
  -spec write(File :: io_device(), Byte :: iodata()) ->
  	'ok' | {'error', posix()}.
  
  write(File, Bytes) when (is_pid(File) orelse is_atom(File)) ->
  
negative.code: advise(_, _, _, _) ->
      {error, badarg}.
  
  -spec read(File :: io_device() | atom(), Size :: non_neg_integer()) ->
  	'eof' | {'ok', [char()] | binary()} | {'error', posix()}.
  
  read(File, Sz) when (is_pid(File) orelse is_atom(File)), is_integer(Sz), Sz >= 0 ->
  