# File lib/openid/store/filesystem.rb, line 100
      def _get_association(filename)
        begin
          assoc_file = File.open(filename, "r")
        rescue Errno::ENOENT
          return nil
        else
          begin
            assoc_s = assoc_file.read
          ensure
            assoc_file.close
          end

          begin
            association = Association.deserialize(assoc_s)
          rescue
            self.remove_if_present(filename)
            return nil
          end

          # clean up expired associations
          if association.expires_in == 0
            self.remove_if_present(filename)
            return nil
          else
            return association
          end
        end
      end