diff --git a/include/hpp/manipulation/graph/fwd.hh b/include/hpp/manipulation/graph/fwd.hh
index 5902917e0fa8d22eac57ddca619768f97b1ad7dd..22cb327cc81181cd0e70faf75c129da4fd9b933c 100644
--- a/include/hpp/manipulation/graph/fwd.hh
+++ b/include/hpp/manipulation/graph/fwd.hh
@@ -18,15 +18,22 @@
 # define HPP_MANIPULATION_GRAPH_FWD_HH
 
 #include <hpp/util/pointer.hh>
+#include <vector>
 
 namespace hpp {
   namespace manipulation {
     namespace graph {
+      HPP_PREDEF_CLASS (Graph);
       HPP_PREDEF_CLASS (Node);
       HPP_PREDEF_CLASS (Edge);
       HPP_PREDEF_CLASS (NodeSelector);
+      typedef boost::shared_ptr < Graph > GraphPtr_t;
+      typedef boost::shared_ptr < Node > NodePtr_t;
       typedef boost::shared_ptr < Edge > EdgePtr_t;
       typedef boost::shared_ptr < NodeSelector > NodeSelectorPtr_t;
+      typedef std::vector < NodePtr_t > Nodes_t;
+      typedef std::vector < EdgePtr_t > Edges_t;
+      typedef std::vector < NodeSelectorPtr_t > NodeSelectors_t;
 
       typedef hpp::core::ConstraintSet ConstraintSet_t;
       typedef hpp::core::ConstraintSetPtr_t ConstraintSetPtr_t;
diff --git a/include/hpp/manipulation/graph/graph.hh b/include/hpp/manipulation/graph/graph.hh
index 5ff9e4a12ed44ba0a87b0b7ba8937e7d6548dd35..22a005159c6ae23473cc8c1097e7f5049966d329 100644
--- a/include/hpp/manipulation/graph/graph.hh
+++ b/include/hpp/manipulation/graph/graph.hh
@@ -14,7 +14,6 @@
 // received a copy of the GNU Lesser General Public License along with
 // hpp-manipulation. If not, see <http://www.gnu.org/licenses/>.
 
-
 #ifndef HPP_MANIPULATION_GRAPHGRAPH_HH
 # define HPP_MANIPULATION_GRAPHGRAPH_HH
 
@@ -30,6 +29,11 @@ namespace hpp {
       class HPP_MANIPULATION_DLLAPI Graph
       {
         public:
+          /// Returns the states of a configuration.
+          virtual Nodes_t getNode(const Configuration_t config) const;
+
+          /// Select randomly outgoing edges of the given nodes.
+          virtual Edges_t chooseEdge(const Nodes_t& node) const;
 
         private:
           /// This list contains a node selector for each end-effector.
@@ -38,7 +42,7 @@ namespace hpp {
           /// A set of constraints that will always be used, for example
           /// stability constraints.
           ConstraintSetPtr_t constraints_;
-      }
+      }; // Class Graph
     } // namespace graph
   } // namespace manipulation
 } // namespace hpp
diff --git a/include/hpp/manipulation/graph/node-selector.hh b/include/hpp/manipulation/graph/node-selector.hh
index b507cfcdf368c0a3a837547f5de214667c884533..e8a2757073ec1204e77a69850ee04436b77f3e5c 100644
--- a/include/hpp/manipulation/graph/node-selector.hh
+++ b/include/hpp/manipulation/graph/node-selector.hh
@@ -29,12 +29,15 @@ namespace hpp {
       {
         public:
           /// Returns the state of a configuration.
-          virtual Node getState(const Configuration_t config) const;
+          virtual NodePtr_t getNode(const Configuration_t config) const;
+
+          /// Select randomly an outgoing edge of the given node.
+          virtual EdgePtr_t chooseEdge(const NodePtr_t& node) const;
 
         private:
           /// List of the states of one end-effector, ordered by priority.
           std::vector< NodeWkPtr_t > orderedStates_;
-      }; //
+      }; // Class NodeSelector
     } // namespace graph
   } // namespace manipulation
 } // namespace hpp