memcached-ext.rb

module Waves
  module Cache

   module Memcached
     module Extensions

       def method_missing(*args, &block)
         @cache.__send__(*args, &block)
       rescue => e
         Waves::Logger.error e.to_s
         nil
       end

     end
   end

  end
end

memcached-ipi.rb

module Waves
  module Cache

    module Memcached
      require 'memcached' and Waves.config.dependencies << 'memcached'
     #  Only un-comment if you understand the implications.
#       require 'memcached-ext'
#       include Waves::Cache::Memcached::Extensions

      def initialize(args)
    ....