The class action is “an exception to the usual rule that litigation is conducted by
 and on
behalf
 of
 the individual nam
ed parties only
.”
Wal-Mart Stores, Inc. v. Dukes
, 131 S.Ct. 2541,
2550 (2011) (quoting
Califano v. Y
amasaki
, 442 U.S. 682, 700-01 (1979)).  In order to justif
y a
departure f
rom
 that rule, “a class representative must be part of the class and ‘possess the same
interest and suf
fer the sam
e injury
’ as the class m
em
bers.”
Id.
(citing
E. Tex. Motor Freight Sys.,
Inc. v. Rodriguez
, 431 U.S. 395, 403 (1977)).  In this regard, Rule 23 contains two sets of
 class
certif
ication requirem
ents set f
orth in Rule 23(a) and (b).