input: Write a function to extract all email addresses from a given string using regular expressions. The function should return a list of all email addresses found in the input string. If no email addresses are found, it should 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 in this string")==[]
  assert find_emails("Multiple emails like info@domain.com, support@domain.com, and contact@domain.com")==['info@domain.com', 'support@domain.com', 'contact@domain.com']
  assert find_emails("This string has @ but no emails")==[]
  assert find_emails("")==[]
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)