# File lib/yaml/stream.rb, line 27
                def emit( io = nil )
            # opts = @options.dup
                        # opts[:UseHeader] = true if @documents.length > 1
            out = YAML.emitter
            out.reset( io || io2 = StringIO.new )
            @documents.each { |v|
                v.to_yaml( out )
            }
            io || ( io2.rewind; io2.read )
                end