input: Write a function to filter a list of email addresses that belong to a particular domain. The function should take a list of email addresses and a domain as input and return a filtered list of email addresses that belong to that domain. If the list is empty, return an empty list.
  assert filter_emails("gmail.com", ["john@gmail.com", "sarah@yahoo.com", "bob@microsoft.com", "sophie@gmail.com"])==["john@gmail.com", "sophie@gmail.com"]
  assert filter_emails("yahoo.com", ["john@gmail.com", "sarah@yahoo.com", "bob@microsoft.com", "sophie@gmail.com"])==["sarah@yahoo.com"]
  assert filter_emails("microsoft.com", ["john@gmail.com", "sarah@yahoo.com", "bob@microsoft.com", "sophie@gmail.com"])==["bob@microsoft.com"]
  assert filter_emails("hotmail.com", ["john@gmail.com", "sarah@yahoo.com", "bob@microsoft.com", "sophie@gmail.com"])==[]
  assert filter_emails("gmail.com", [])==[]
output: def filter_emails(domain, emails):
      return [email for email in emails if email.endswith(f"@{domain}")]