input: Write a function to design a web server in Python using the Flask framework that serves a JSON object containing the current temperature for a city based on the city name given in the request. The function should be named `setup_temperature_server` and should return the Flask app object. Ensure the endpoint '/getTemp' accepts POST requests with a JSON payload containing the city name, and returns the temperature in the JSON response.
  
  from flask import Flask, request
  import requests
  import json
  
  def setup_temperature_server():
      app = Flask(__name__)
  
      @app.route('/getTemp', methods=['POST'])
      def get_temp():
          city = request.json['city']
          url = 'http://api.openweathermap.org/data/2.5/weather?q={}&APPID=xxxxxx'
          r = requests.get(url.format(city))
          weather = json.loads(r.text)
          return {'temperature': weather['main']['temp']}
  
      return app
  
  assert setup_temperature_server().testing.post('/getTemp', json={'city': 'London'}).status_code == 200
  assert 'temperature' in setup_temperature_server().testing.post('/getTemp', json={'city': 'London'}).json
  assert setup_temperature_server().testing.post('/getTemp', json={'city': 'NonExistentCity'}).status_code != 200
  assert setup_temperature_server().testing.post('/getTemp', json={'city': 'Paris'}).json['temperature'] != None
  assert setup_temperature_server().testing.post('/getTemp', json={'city': 'Tokyo'}).json['temperature'] != None
output: 
  def setup_temperature_server():
      app = Flask(__name__)
  
      @app.route('/getTemp', methods=['POST'])
      def get_temp():
          city = request.json['city']
          url = 'http://api.openweathermap.org/data/2.5/weather?q={}&APPID=xxxxxx'
          r = requests.get(url.format(city))
          weather = json.loads(r.text)
          return {'temperature': weather['main']['temp']}
  
      return app
  