changing level of assignment to signed int

Former-commit-id: 59f53da1de [formerly e0742f0a16]
Former-commit-id: 355edf6c56

src/storage/jani/Assignment.cpp

@@ -38,7 +38,7 @@ namespace storm  {
             this->setAssignedExpression(this->getAssignedExpression().substitute(substitution));
         }
         
-        uint64_t Assignment::getLevel() const {
+        int64_t Assignment::getLevel() const {
             return level;
         }
         

src/storage/jani/Assignment.h

@@ -50,7 +50,7 @@ namespace storm {
             /*!
              * Retrieves the level of the assignment.
              */
-            uint64_t getLevel() const;
+            int64_t getLevel() const;
             
             friend std::ostream& operator<<(std::ostream& stream, Assignment const& assignment);