code: def test_handle_error_does_not_duplicate_content_length(self, app):
      api = restplus.Api(app)
  
      # with self.app.test_request_context("/foo"):
      response = api.handle_error(BadRequest())
      assert len(response.headers.getlist("Content-Length")) == 1
  
imports: from __future__ import unicode_literals
  import json
  import logging
  import pytest
  from flask import Blueprint, abort
  from flask.signals import got_request_exception
  from werkzeug.exceptions import HTTPException, BadRequest, NotFound, Aborter
  from werkzeug.http import quote_etag, unquote_etag
  import flask_restplus
label_desc: Use image node_id 27 for calling the ErrorsTest obj's underlying member method code with example usage: obj.test_handle_error_does_not_duplicate_content_length(app) without return types