# File lib/yaml/rubytypes.rb, line 163
        def to_yaml( opts = {} )
                YAML::quick_emit( is_complex_yaml? ? object_id : nil, opts ) do |out|
            if is_binary_data?
                out.scalar( "tag:yaml.org,2002:binary", [self].pack("m"), :literal )
            elsif to_yaml_properties.empty?
                out.scalar( taguri, self, self =~ /^:/ ? :quote2 : to_yaml_style )
            else
                out.map( taguri, to_yaml_style ) do |map|
                    map.add( 'str', "#{self}" )
                    to_yaml_properties.each do |m|
                        map.add( m, instance_variable_get( m ) )
                    end
                end
            end
        end
        end