typedef std::vector<SectionWriter*> SectionWriters;

     typedef std::vector<SectionWriter*> SectionWriters;

     SectionWriters writers;

     SectionWriters writers;

   };

   };

   /// \brief SectionWriter for writing a graph's nodeset.

   /// \brief SectionWriter for writing a graph's nodeset.

   ///

   ///

   /// The lemon format can store multiple graph nodesets with several maps.

   /// The lemon format can store multiple graph nodesets with several maps.

   /// The nodeset section's header line is \c \@nodeset \c nodeset_name, but 

   /// The nodeset section's header line is \c \@nodeset \c nodeset_name, but 

   /// the \c nodeset_name may be empty.

   /// the \c nodeset_name may be empty.

     const Graph& graph;   

     const Graph& graph;   

     std::string name;

     std::string name;

   };

   };

   /// \brief SectionWriter for writing a graph's edgesets.

   /// \brief SectionWriter for writing a graph's edgesets.

   ///

   ///

   /// The lemon format can store multiple graph edgesets with several maps. 

   /// The lemon format can store multiple graph edgesets with several maps. 

   /// The edgeset section's header line is \c \@edgeset \c edgeset_name, but 

   /// The edgeset section's header line is \c \@edgeset \c edgeset_name, but 

   /// the \c edgeset_name may be empty.

   /// the \c edgeset_name may be empty.

     std::string name;

     std::string name;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > nodeLabelWriter;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > nodeLabelWriter;

   };

   };

   /// \brief SectionWriter for writing a undirected edgeset.

   /// \brief SectionWriter for writing a undirected edgeset.

   ///

   ///

   /// The lemon format can store multiple undirected edgesets with several 

   /// The lemon format can store multiple undirected edgesets with several 

   /// maps. The undirected edgeset section's header line is \c \@uedgeset 

   /// maps. The undirected edgeset section's header line is \c \@uedgeset 

   /// \c uedgeset_name, but the \c uedgeset_name may be empty.

   /// \c uedgeset_name, but the \c uedgeset_name may be empty.

     std::string name;

     std::string name;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > nodeLabelWriter;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > nodeLabelWriter;

   };

   };

   /// \brief SectionWriter for writing named nodes.

   /// \brief SectionWriter for writing named nodes.

   ///

   ///

   /// The nodes section's header line is \c \@nodes \c nodes_name, but the

   /// The nodes section's header line is \c \@nodes \c nodes_name, but the

   /// \c nodes_name may be empty.

   /// \c nodes_name may be empty.

   ///

   ///

     typedef std::vector<std::pair<std::string, const Node*> > NodeWriters;

     typedef std::vector<std::pair<std::string, const Node*> > NodeWriters;

     NodeWriters writers;

     NodeWriters writers;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > labelWriter;

     std::auto_ptr<_writer_bits::LabelWriterBase<Node> > labelWriter;

   };

   };

   /// \brief SectionWriter for writing named edges.

   /// \brief SectionWriter for writing named edges.

   ///

   ///

   /// The edges section's header line is \c \@edges \c edges_name, but the

   /// The edges section's header line is \c \@edges \c edges_name, but the

   /// \c edges_name may be empty.

   /// \c edges_name may be empty.

   ///

   ///

     EdgeWriters writers;

     EdgeWriters writers;

     std::auto_ptr<_writer_bits::LabelWriterBase<Edge> > labelWriter;

     std::auto_ptr<_writer_bits::LabelWriterBase<Edge> > labelWriter;

   };

   };

   /// \brief SectionWriter for writing named undirected edges.

   /// \brief SectionWriter for writing named undirected edges.

   ///

   ///

   /// The undirected edges section's header line is \c \@uedges 

   /// The undirected edges section's header line is \c \@uedges 

   /// \c uedges_name, but the \c uedges_name may be empty.

   /// \c uedges_name, but the \c uedges_name may be empty.

   ///

   ///

     EdgeWriters edgeWriters;

     EdgeWriters edgeWriters;

     std::auto_ptr<_writer_bits::LabelWriterBase<Edge> > edgeLabelWriter;

     std::auto_ptr<_writer_bits::LabelWriterBase<Edge> > edgeLabelWriter;

   };

   };

   /// \brief SectionWriter for attributes.

   /// \brief SectionWriter for attributes.

   ///

   ///

   /// The lemon format can store multiple attribute set. Each set has

   /// The lemon format can store multiple attribute set. Each set has

   /// the header line \c \@attributes \c attributes_name, but the 

   /// the header line \c \@attributes \c attributes_name, but the 

   /// attributeset_name may be empty.

   /// attributeset_name may be empty.