Issue 986: sonar issues

Author: walaniam

boat-scaffold/src/test/java/com/backbase/oss/codegen/java/BoatCommonJavaCodeGenTests.java

@@ -154,7 +154,7 @@ private void assertVariableDeclarator(CompilationUnit requestClass, String field
             .findAll(FieldDeclaration.class)
             .stream()
             .flatMap(field -> field.getChildNodes().stream())
-            .filter(node -> node instanceof VariableDeclarator)
+            .filter(VariableDeclarator.class::isInstance)
             .map(VariableDeclarator.class::cast)
             .filter(declarator -> declarator.getName().getIdentifier().equals(fieldName))
             .findFirst()