# File lib/fakefs/file.rb, line 280
    def self.chown(owner_int, group_int, filename)
      file = FileSystem.find(filename)

      if owner_int && owner_int != -1
        owner_int.is_a?(Integer) || fail(TypeError,
                                         "can't convert String into Integer")
        file.uid = owner_int
      end
      if group_int && group_int != -1
        group_int.is_a?(Integer) || fail(TypeError,
                                         "can't convert String into Integer")
        file.gid = group_int
      end
    end