public void writeArrayNull(long features) {
        String raw;
        if ((features & (MASK_NULL_AS_DEFAULT_VALUE | MASK_WRITE_NULL_LIST_AS_EMPTY)) != 0) {
            raw = "[]";
        } else {
            raw = "null";
        }
        writeRaw(raw);
    }
If ReferenceDetection has been set, returns the path of the current object, otherwise returns null
@since 2.0.51
@return the path of the current object
core/src/main/java/com/alibaba/fastjson2/JSONWriter.java