code: def test_headers(self, app):
      api = restplus.Api(app)
  
      parser = api.parser()
      parser.add_argument(
          "X-Header-1", location="headers", default="xxx"
      )
      parser.add_argument(
          "X-Header-2", location="headers", required=True
      )
  
      @api.route("/headers/")
      class TestHeaders(restplus.Resource):
          @api.doc("headers")
          @api.expect(parser)
          def get(self):
              pass
  
      data = api.as_postman(urlvars=True)
  
      validate(data, schema)
      request = data["requests"][0]
      headers = dict(
          r.split(":") for r in request["headers"].splitlines()
      )
  
      assert headers["X-Header-1"] == "xxx"
      assert headers["X-Header-2"] == ""
  
imports: from __future__ import unicode_literals, absolute_import
  import json
  from os.path import join, dirname
  from jsonschema import validate
  from werkzeug.datastructures import FileStorage
  import flask_restplus
  from six.moves.urllib.parse import parse_qs, urlparse
label_desc: Use image node_id 12 for calling the PostmanTest obj's underlying member method code with example usage: obj.test_headers(app) without return types