def storage_response
          resp_header, = read_response
          return nil if resp_header.not_found?
          return false if resp_header.not_stored? # Not stored, normal status for add operation

          raise_on_not_ok!(resp_header)
          resp_header.cas
        end
#
Response for a storage operation.  Returns the cas on success.  False
if the value wasn't stored.  And raises an error on all other error
codes from memcached.
#