code: def ignore_media?(type, part)
        ignores = config['ignore'][type] || []
        ignore   = ignores.detect{ |test| filename?(part) == test}
        ignore ||= ignores.detect{ |test| filename?(part) =~ test if test.is_a?(Regexp) }
        ignore ||= ignores.detect{ |test| part.body.decoded.strip =~ test if test.is_a?(Regexp) }
        ignore ||= (part.body.decoded.strip.size == 0 ? true : nil)
        ignore.nil? ? false : true
      end
docs: Helper for process template method to determine if media contained in a
   part should be ignored.  Producers should override this method to return
   true for media such as images that are advertising, carrier logos, etc.
   See the ignore section in the discussion of the built-in configuration.