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: option.rb
    path of file: ./repos/konfig/lib/konfig
    
    the code of the file until where you have to start completion: require "ostruct"

module Konfig
  class Option < OpenStruct
    include Enumerable

    def keys
      marshal_dump.key
    
    def validate!
      if Konfig.configuration.schema
        v_res = Konfig.configuration.schema.(self.marshal_dump)

        unless v_res.success?
          error = Konfig::ValidationError.format(v_res)
          if Konfig.configuration.fail_on_validation
            raise Konfig::ValidationError.new("Config validation failed:\n\n#{error}")
          else
            Konfig.configuration.logger.error "Config validation failed:\n\n#{error}"
          end