input: Write a function to scrape all question links related to 'machine learning' from Quora.
  assert len(scrape_machine_learning_questions()) > 0
  assert isinstance(scrape_machine_learning_questions(), list)
  assert all(isinstance(question, str) for question in scrape_machine_learning_questions())
output: def scrape_machine_learning_questions():
      import requests
      from bs4 import BeautifulSoup
  
      url = "https://www.quora.com/search?q=machine+learning"
      response = requests.get(url)
      soup = BeautifulSoup(response.text, 'html.parser')
  
      questions = []
      for link in soup.find_all('a', href=True):
          href = link['href']
          if '/question/' in href:
              questions.append('https://www.quora.com' + href)
      
      return questions