input: Write a function to scrape the table at the given URL and extract the planets information (name, mass, and distance from the sun). The function should return a list of dictionaries where each dictionary contains the name, mass, and distance from the sun of a planet. If no planets are found, the function should return an empty list.
  
  
  def scrape_planets(url):
      import requests
      from bs4 import BeautifulSoup
  
      page = requests.get(url)
      soup = BeautifulSoup(page.content, 'lxml')
  
      planets_table = soup.find('table', class_='wikitable sortable')
  
      planets = []
      if planets_table:
          for row in planets_table.find_all('tr'):
              if row.find('th'):
                  continue
              cells = row.find_all('td')
              planets.append({
                  'name': cells[0].text,
                  'mass': cells[2].text,
                  'distance_from_sun': cells[5].text
              })
  
      return planets
  
  # Test cases
  assert scrape_planets('https://en.wikipedia.org/wiki/List_of_gravitationally_rounded_objects_of_the_Solar_System') != []
  assert scrape_planets('https://en.wikipedia.org/wiki/Non_Existent_Url') == []
  assert scrape_planets('https://en.wikipedia.org/wiki/List_of_(TestUrl)') == []
  
output: def scrape_planets(url):
      import requests
      from bs4 import BeautifulSoup
  
      page = requests.get(url)
      soup = BeautifulSoup(page.content, 'lxml')
  
      planets_table = soup.find('table', class_='wikitable sortable')
  
      planets = []
      if planets_table:
          for row in planets_table.find_all('tr'):
              if row.find('th'):
                  continue
              cells = row.find_all('td')
              planets.append({
                  'name': cells[0].text,
                  'mass': cells[2].text,
                  'distance_from_sun': cells[5].text
              })
  
      return planets