# File lib/rgl/rdot.rb, line 265
265:     def to_s (t = '')
266:       hdr = t + "#{@dot_string} #{@name} {\n"
267: 
268:       options = @options.to_a.collect{ |name, val|
269:         val && name != 'label' ? 
270:           t + $tab + "#{name} = #{val}" : 
271:           name ? t + $tab + "#{name} = \"#{val}\"" : nil
272:       }.compact.join( "\n" ) + "\n"
273: 
274:       nodes = @nodes.collect{ |i|
275:         i.to_s( t + $tab )
276:       }.join( "\n" ) + "\n" 
277:       hdr + options + nodes + t + "}\n"
278:     end