public void setSerializeNullValues(boolean serializeNullValues) {
        this.serializeNullValues = serializeNullValues;
    }
Specifies if {@code null} values returned from getters are serialized.

@param serializeNullValues Set to true to serialize {@code null} values.
smithy-model/src/main/java/software/amazon/smithy/model/node/NodeMapper.java