input: Write a function to extract all email addresses from a given string using regular expressions. If the string does not contain any email addresses, return an empty list.
  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("Another example: support@example.org")==["support@example.org"]
  assert find_emails("")==[]
output: import re
  
  def find_emails(text):
      return re.findall(r'[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}', text)