Perform the solve.

def solve(self):
        """Perform the solve.
        """
        with log_duration(self._print, "memcache get (resolve) took %s"):
            solver_dict = self._get_cached_solve()

        if solver_dict:
            self.from_cache = True
            self._set_result(solver_dict)
        else:
            self.from_cache = False
            solver = self._solve()
            solver_dict = self._solver_to_dict(solver)
            self._set_result(solver_dict)

            with log_duration(self._print, "memcache set (resolve) took %s"):
                self._set_cached_solve(solver_dict)