///Runs the second phase of the preflow algorithm.

     ///Runs the second phase of the preflow algorithm.

     ///The preflow algorithm consists of two phases, this method runs

     ///The preflow algorithm consists of two phases, this method runs

     ///returns the value of a maximum flow, \ref minCut returns a

     ///returns the value of a maximum flow, \ref minCut returns a

     ///minimum cut, while the methods \ref minMinCut and \ref

     ///minimum cut, while the methods \ref minMinCut and \ref

     ///maxMinCut return the inclusionwise minimum and maximum cuts of

     ///maxMinCut return the inclusionwise minimum and maximum cuts of

     ///minimum value, resp.  \pre \ref phase1 must be called before.

     ///minimum value, resp.  \pre \ref phase1 must be called before.

     void phase2()

     void phase2()