Setup a new solver tree for the bfs instance BfsInstance. The tree will be associated with BfsInstance; BfsInstance must not already have a solver tree associated with it. Once the solver tree is setup, it can be optimised via solve/1.
This is a simplified version of solver_setup/3, it is equivalent to calling solver_setup/3 with the following default options:
solver_setup(OptSense, Solver, [])