# File lib/xmlsimple.rb, line 296 def normalize_option_names(options, known_options) return nil if options.nil? result = Hash.new options.each { |key, value| lkey = key.downcase lkey.gsub!(/_/, '') if !known_options.member?(lkey) raise ArgumentError, "Unrecognised option: #{lkey}." end result[lkey] = value } result end