Revert "Remove an unused member"
Revert "Remove an unused member"

This reverts commit 6171ed4dece769c51f316d689a694888d0c51ea0.

myokoym/groonga,naoa/groonga,kenhys/groonga,redfigure/groonga,redfigure/groonga,komainu8/groonga,cosmo0920/groonga,redfigure/groonga,myokoym/groonga,cosmo0920/groonga,myokoym/groonga,naoa/groonga,naoa/groonga,redfigure/groonga,hiroyuki-sato/groonga,groonga/groonga,cosmo0920/groonga,cosmo0920/groonga,hiroyuki-sato/groonga,kenhys/groonga,hiroyuki-sato/groonga,naoa/groonga,naoa/groonga,groonga/groonga,hiroyuki-sato/groonga,komainu8/groonga,naoa/groonga,groonga/groonga,kenhys/groonga,naoa/groonga,redfigure/groonga,komainu8/groonga,myokoym/groonga,groonga/groonga,cosmo0920/groonga,myokoym/groonga,kenhys/groonga,cosmo0920/groonga,kenhys/groonga,groonga/groonga,myokoym/groonga,hiroyuki-sato/groonga,hiroyuki-sato/groonga,komainu8/groonga,komainu8/groonga,myokoym/groonga,kenhys/groonga,redfigure/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,groonga/groonga,myokoym/groonga,groonga/groonga,redfigure/groonga,komainu8/groonga,komainu8/groonga,cosmo0920/groonga,komainu8/groonga,hiroyuki-sato/groonga,hiroyuki-sato/groonga,redfigure/groonga,naoa/groonga,cosmo0920/groonga