code: def write_compacted(g):
      
      d_nodes = {}
      d_edges = {}
  
      def conv(value):
          if isinstance(value, basestring):
              return value.strip('"')
          else:
              return value
  
      for node in g.nodes():
          label = None
          attrs = []
  
          for k, v in sorted(g.node_attributes(node)):
              v_ = conv(v)
              if k == "label":
                  label = v_
              else:
                  attrs.append((k, v_))
  
          value = (node, label) if label else node
          d_nodes.setdefault(tuple(attrs), []).append(value)
  
      for edge in g.edges():
          attrs = [(k, conv(v)) for k, v in sorted(g.edge_attributes(edge))]
          label = str(g.edge_label(edge))
          value = tuple(list(edge) + [label]) if label else edge
          d_edges.setdefault(tuple(attrs), []).append(tuple(value))
  
      doc = dict(nodes=d_nodes.items(), edges=d_edges.items())
      contents = str(doc)
      return contents
docs: Write a graph in our own compacted format.
  
      Returns:
          str.