Summary: Warning in release build.
Test Plan: Make release and make all
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D52305
This is an Env implementation that mirrors all storage-related methods on
two different backend Env's and verifies that they return the same
results (return status and read results). This is useful for implementing
a new Env and verifying its correctness.
Signed-off-by: Sage Weil <sage@redhat.com>