[erlang-questions] mime_decode_string/1?

[Catsunny]

Hi,
I wonder if there is something wrong in the erlang documentation->STDLIB  
Reference->base64? The documentation says:

base64
MODULE
base64
MODULE SUMMARY
Implements base 64 encode and decode, see RFC2045.
DESCRIPTION
Implements base 64 encode and decode, see RFC2045.

EXPORTS
encode(Data) -> Base64
encode_to_string(Data) -> Base64String


Types:

Data = string() | binary()
Base64 = binary()
Base64String = string()


Encodes a plain ASCII string into base64. The result will be 33% larger  
than the data.

decode(Base64) -> Data
decode_to_string(Base64) -> DataString
mime_decode(Base64) -> Data
mime_decode_string(Base64) -> DataString


Types:

Base64 = string() | binary()
Data = binary()
DataString = string()


Decodes a base64 encoded string to plain ASCII. The string should only  
consist of characters in the base64 set, see RFC4648. mime_decode/1 and  
mime_decode_to_string/1 strips away illegal characters, while decode/1 and  
decode_to_string/1 fails if an illegal charactrer is found.


--------------------------------------------------------------------------------
stdlib 1.15.1
Copyright ? 1991-2008 Ericsson AB

All the functions is ok except the last one, mime_decode_string/1:
11> base64:mime_decode_string(base64:encode_to_string("我们")).
** exception error: undefined function base64:mime_decode_string/1.
Is this an error in the library reference manual?

Thank you!
catsunny