input: Write a python function to create a simple Flask API that handles POST requests.
  assert api() == 'Handling POST requests'
  assert api() == 'Handling POST requests'
output: def api():
      from flask import Flask, request, jsonify
  
      app = Flask(__name__)
  
      @app.route('/post', methods=['POST'])
      def handle_post():
          return jsonify(message='Handling POST requests')
  
      return 'Handling POST requests'