input: Write a function to fetch product data from a given URL and save it to a CSV file using pandas.
  assert fetch_and_save_products('https://www.example.com/')==None
  assert pd.read_csv('product_price.csv').shape[0] > 0
output: import pandas as pd
  import requests
  
  def fetch_and_save_products(url):
      response = requests.get(url)
      response.raise_for_status()  # Ensure we notice bad responses
      data = response.json()  # Assuming the response is in JSON format
      
      df = pd.DataFrame(data)
      df.to_csv('product_price.csv', index=False)