input: Write a function to extract all email addresses from a given string. If no email addresses are found, return an empty list. Use a regular expression to identify and return the email addresses.
  assert find_emails("This is an example with two emails: john@example.com, and jane@example.com")==['john@example.com', 'jane@example.com']
  assert find_emails("No emails here")==[]
  assert find_emails("One email: alice@example.net")==['alice@example.net']
  assert find_emails("")==[]
  assert find_emails("invalid@email, valid@example.org, another_invalid@email")==['valid@example.org']
output: import re
  
  def find_emails(text):
      pattern = r'\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b'
      return re.findall(pattern, text)