This avoids dynamic construction of the private class. According to
the benchmark we go from 4,550 to 3,900 instruction reads per iteration.
(without change 32629676 the baseline is 5,600)
Change-Id: I5df925e30dbd49bdde87173e481820574ce5abe1
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>