code: public Serializer<?> nullSafeSerializerFor( TypeFactory<?> type ) {
          if (type instanceof TupleFactory) {
              return ((TupleFactory<?>)type).getSerializer(this);
          }
          return serializers.nullSafeSerializerFor(type.getType());
      }
docs: Obtain serializer for the given value type that can handle null values. This is used in Tuples
  serialization. (See MODE-2490). Note: {@code type} must itself still not be null, but the values
  to be serialized <emph>can</emph> be null.
  
  @param type the type; may not be null
  @return the serializer