public JSONObject fluentPut(String key, Object value) {
        put(key, value);
        return this;
    }
Chained addition of elements

<pre>
JSONObject object = new JSONObject().fluentPut("a", 1).fluentPut("b", 2).fluentPut("c", 3);
</pre>

@param key key with which the specified value is to be associated
@param value value to be associated with the specified key
core/src/main/java/com/alibaba/fastjson2/JSONObject.java