def max_staleness(value)
      if /\A\d+\z/ =~ value
        int = value.to_i

        if int >= 0 && int < 90
          log_warn("max staleness must be either 0 or greater than 90: #{value}")
        end

        return int
      end

      log_warn("Invalid max staleness value: #{value}")
      nil
    end
def max_staleness(value)
      if /\A\d+\z/ =~ value
        int = value.to_i

        if int >= 0 && int < 90
          log_warn("max staleness must be either 0 or greater than 90: #{value}")
        end

        return int
      end

      log_warn("Invalid max staleness value: #{value}")
      nil
    end
Parses the max staleness value, which must be either "0" or an integer greater or equal to 90.

 @param value [ String ] The max staleness string.

 @return [ Integer | nil ] The max staleness integer parsed out if it is valid, otherwise nil
   (and a warning will be logged).