public PrimitiveValue applicableNullValue()
    {
        if (null != nullValue)
        {
            return nullValue;
        }

        return primitiveType.nullValue();
    }
The most applicable null value for the encoded type.

@return most applicable null value for the encoded type.
sbe-tool/src/main/java/uk/co/real_logic/sbe/ir/Encoding.java