retrieves namespace from filename.
retrieves namespace from filename.

hiroyuki-seki/hryky-codebase,hiroyuki-seki/hryky-codebase,hiroyuki-seki/hryky-codebase,hiroyuki-seki/hryky-codebase,hiroyuki-seki/hryky-codebase,hiroyuki-seki/hryky-codebase