You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: base.rb
    path of file: ./repos/versioncake/lib/versioncake/response_strategy
    
    the code of the file until where you have to start completion: module VersionCake
  module ResponseStrategy
    class Base
      def execute(_context, _status, _headers, _response)
        raise Exception, "
    
      def self.lookup(strategy)
        case strategy
          when String, Symbol
            strategy_name = "#{strategy}_strategy".camelize
            begin
              VersionCake::ResponseStrategy.const_get(strategy_name).new
            rescue
              raise Exception, "Unknown VersionCake response strategy #{strategy_name}"
            end