		IO::Adapter β¤

   [Ѹ]
	KEY = STR		
	*   = ơ


   [¤]

   1)
	getline()  split() Ƥ륳ɤ
	get_next_value()  ARRAY_REF ȤƼȤ褦ѹ

   2)
	address -> # address 
	replace(key, \@argv) ȤäƹԤʤ

	 replace() ϻȤäƤʤ


   [Υ᥽åɤϻȤäƤ]
	get_next_key		()		STR
	add			(KEY)		*
				(KEY, STR)	*	׳ĥ
				(KEY, [])	*	׳ĥ
	delete			(KEY)		*

	 Mail::Delivery::SMTP ǤĤƤ
	getpos			()		NUM
	setpos			(NUM)		NUM
	eof			()		*

   [Υ᥽åɤϲɤ;Ϥʤ]
	touch			(ʤ)	*

   [׺Ƽ(ϤȤꤢȤäƤʤ)]
	getline			()		STR	 implemented.
				join by space.
	get_value_as_str	(KEY)		STR	׳ĥ
	get_value_as_array_ref	(KEY)		[]	׳ĥ

   [ removed ]
	replace			(KEY, STR)	*	׳ĥ
				(KEY, [])	*	׳ĥ

*** TODO ***

   File::Sequence
	IO::Adapter ͳˤ٤Ǥ

   Tie::JournaledFile
	IO::Adapter  journaled file 򥵥ݡȤƤۤ

	[BUG] ?
	 negative cache äƤޤäƤʤ
		find()  ->{}  negative cache
		ְäͭˤʤäƤ󤸤ʤΡ

