input: Write a function to create a web scraper using Python's Selenium that retrieves data from an online store. The function should initialize a Firefox session, navigate to the online store's homepage, perform a search for "shoes," retrieve and print the names of products displayed on the result page, and then close the browser window.
  
  ### Function Header:
  
  def web_scraper():
  
  
  ### Assert Test Cases:
  #### Test Case 1:
  
  assert web_scraper() == "Expected output based on the searched products."
  
  
  #### Test Case 2:
  
  assert web_scraper() == "Expected output based on the searched products."
  
output: from selenium import webdriver
  from selenium.webdriver.common.by import By
  from selenium.webdriver.common.keys import Keys
  import time
  
  def web_scraper():
      driver = webdriver.Firefox()
      driver.get("https://www.example-online-store.com")
      search_box = driver.find_element(By.NAME, "q")
      search_box.send_keys("shoes")
      search_box.send_keys(Keys.RETURN)
      time.sleep(2)
      product_names = driver.find_elements(By.CLASS_NAME, "product-name")
      for name in product_names:
          print(name.text)
      driver.quit()