ff53b0ef_f_Memcache___Heroku_Dev_Center__Operation
[Description] Sets a new value as long as the value hasn’t been changed by another process. Thread safe. [Operation] 
CAS (or set with a version)
S e t w i t h e x p i r a t i o n
F l u s h
I n c r e m e n t
D e c r e m e n t
A p p e n d
P r e p e n d
C A S ( o r s e t w i t h a v e r s i o n )
Getting the Most Out of Memcache | Heroku Dev Center