input: Write a function to filter a list of email addresses and return only those that belong to a specified domain. The function should take two arguments: a list of email addresses and a domain string. It should return a new list containing only the email addresses that end with the specified domain. If the input list is empty, the function should return an empty list.
  assert filter_emails(["john@gmail.com", "sarah@yahoo.com", "bob@microsoft.com", "sophie@gmail.com"], "@gmail.com") == ["john@gmail.com", "sophie@gmail.com"]
  assert filter_emails(["alice@hotmail.com", "james@outlook.com"], "@hotmail.com") == ["alice@hotmail.com"]
  assert filter_emails([], "@gmail.com") == []
  assert filter_emails(["mike@yahoo.com", "jane@yahoo.com"], "@yahoo.com") == ["mike@yahoo.com", "jane@yahoo.com"]
  assert filter_emails(["john@apple.com", "sara@apple.com"], "@microsoft.com") == []
output: def filter_emails(emails, domain):
      return [email for email in emails if email.endswith(domain)]