# File lib/bee_util.rb, line 362
      def check_hash(hash, description)
        # check for mandatory keys
        for key in description.keys
          case description[key]
          when :mandatory
            error "Missing mandatory key '#{key}'" if not hash.has_key?(key)
          when :optional
          else
            error "Unknown symbol '#{description[key]}'"
          end
        end
        # look for unknown keys in hash
        for key in hash.keys
          error "Unknown key '#{key}'" if not description.keys.member?(key)
        end
      end