# File lib/sqlite3/driver/dl/driver.rb, line 125
    def set_authorizer( db, data=nil, &block )
      @authorizer_handler = block

      unless @authorizer_handler_callback
        @authorizer_handler_callback = ::DL.callback( "IPIPPPP"
        ) do |cookie,mode,a,b,c,d|
          @authorizer_handler.call( cookie, mode,
            a&&a.to_s, b&&b.to_s, c&&c.to_s, d&&d.to_s ) || 0
        end
      end

      API.sqlite3_set_authorizer( db, block&&@authorizer_handler_callback,
        data )
    end