declare fetch target date
divide sources
declare Tweet class.
device convert logic.
refactor: modify __slot__ -> __slots__
modify initialize logic, declare-rule.
declare base-class of Tweet
refactor: modify testcase.
refactor: write Exception message.
follow pattern don't have %z
ReTweet.
modify argument validation.
definition commands.(yet not working)
dummy implement "fetch".
divide fetch logic and display logic.
use Tweet.id as int not string.
refactor
remove support python3.2, try-add support python3.4
refactor for PEP8(ignore E501)
Twinkerer.build_title