fix compiler warning.
@@ -111,7 +111,7 @@ public class SolverVisitorTest extends SolverBasedTest0 {
}
/** visit a constant and iore other opeations. */
- private final class ConstantsVisitor extends DefaultFormulaVisitor<Formula> {
+ private static final class ConstantsVisitor extends DefaultFormulaVisitor<Formula> {
private final List<Object> found = new ArrayList<>();
