code: def post_json(self, url, data, status=200, **kwargs):
      response = self.post(
          url,
          data=json.dumps(data),
          headers={"content-type": "application/json"},
      )
      assert response.status_code == status
      assert response.content_type == "application/json"
      return json.loads(response.data.decode("utf8"))
  
file_path: flask-restplus/tests/conftest.py
imports: from __future__ import unicode_literals
  import json
  import pytest
  from flask import Flask, Blueprint
  from flask.testing import FlaskClient
  import flask_restplus
label_desc: Use image node_id 3 for calling the TestClient obj's underlying member method code with example usage: obj.post_json(url, data, status) and returns: json