Added eager nullability and type checks of values and functions passed to ChronicleMap, if is probable that they won't be passed (and checked) inside contexts, if, say the key is absent in the map

src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java

@@ -370,6 +370,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
         }
     }
 
+    @Override
     final void checkValue(Object value) {
         if (vClass != Void.class && !vClass.isInstance(value)) {
             throw new ClassCastException("Value must be a " + vClass.getName() +