# File lib/active_resource/base.rb, line 603
      def prefix=(value = '/')
        # Replace :placeholders with '#{embedded options[:lookups]}'
        prefix_call = value.gsub(/:\w+/) { |key| "\#{URI.parser.escape options[#{key}].to_s}" }

        # Clear prefix parameters in case they have been cached
        @prefix_parameters = nil

        silence_warnings do
          # Redefine the new methods.
          instance_eval "def prefix_source() \"\#{value}\" end\ndef prefix(options={}) \"\#{prefix_call}\" end\n", __FILE__, __LINE__ + 1
        end
      rescue Exception => e
        logger.error "Couldn't set prefix: #{e}\n  #{code}" if logger
        raise
      end