Performance test(ignore) for add
----------------------------
(without saving json)

1K test:
0.05user 0.00system 0:00.05elapsed 98%CPU (0avgtext+0avgdata 5916maxresident)k
0inputs+0outputs (0major+731minor)pagefaults 0swaps

10K test:
0.53user 0.08system 0:00.62elapsed 99%CPU (0avgtext+0avgdata 27756maxresident)k
0inputs+0outputs (0major+6271minor)pagefaults 0swaps

100K test:
5.62user 0.98system 0:06.65elapsed 99%CPU (0avgtext+0avgdata 249736maxresident)k
0inputs+0outputs (0major+61925minor)pagefaults 0swaps

1M test:
61.65user 9.54system 1:11.41elapsed 99%CPU (0avgtext+0avgdata 2470252maxresident)k
104inputs+0outputs (1major+620327minor)pagefaults 0swaps

App naive test: (show that I'm right)
-------------------------
show naive.rfakesh
show naive.json
run bin/hust-ds < naive.rfakesh

App add/rm/get test:
-----------------------------
show T-100ktest.json
show T-10ktest.json
show 1mtest.json

App test:
-----------------------------
load T-100ktest.json
indirect friend 1
(
1 have friend 24724 67914 83663

Person 24724 
Friends: 37332 82062 89565 97152
Person 67914
Friends: 696 5717 18178 27708 38184 56586 57932 64183 77364 83745 
Person 83663
Friends: 1479 16615 25173 33595 36756 45544 58074 66831 70693 77881 83581 89472 

indirect friend 1
ANSWER: 89472 83581 70693 66831 58074 36756 5717 18178 696 45544 77364 33595 37332 1479 77881 82062 83745 27708 38184 25173 56586 97152 57932 89565 64183 16615 

rfaketerm 0.3.1 ~ rm friend 1 83663
1 -/> 83663
rfaketerm 0.3.1 ~ indirect friend 1
64183 57932 56586 38184 27708 83745 82062 37332 89565 77364 97152 696 18178 5717 

)
no common found... skip
