added some assertions in game-based model checker

Former-commit-id: 6d7e8770b2

src/modelchecker/abstraction/GameBasedMdpModelChecker.cpp

@@ -185,6 +185,11 @@ namespace storm {
             storm::utility::graph::GameProb01Result<Type> prob0Max = storm::utility::graph::performProb0(game, transitionMatrixBdd, game.getStates(constraintExpression), targetStates, player1Direction, storm::OptimizationDirection::Maximize, false, false);
             storm::utility::graph::GameProb01Result<Type> prob1Max = storm::utility::graph::performProb1(game, transitionMatrixBdd, game.getStates(constraintExpression), targetStates, player1Direction, storm::OptimizationDirection::Maximize, true, true);
             
+            STORM_LOG_ASSERT(prob0Min.hasPlayer1Strategy(), "Unable to proceed without strategy.");
+            STORM_LOG_ASSERT(prob0Min.hasPlayer2Strategy(), "Unable to proceed without strategy.");
+            STORM_LOG_ASSERT(prob1Max.hasPlayer1Strategy(), "Unable to proceed without strategy.");
+            STORM_LOG_ASSERT(prob1Max.hasPlayer2Strategy(), "Unable to proceed without strategy.");
+
             STORM_LOG_DEBUG("Min: " << prob0Min.states.getNonZeroCount() << " no states, " << prob1Min.states.getNonZeroCount() << " yes states.");
             STORM_LOG_DEBUG("Max: " << prob0Max.states.getNonZeroCount() << " no states, " << prob1Max.states.getNonZeroCount() << " yes states.");