'Regression for #13259 - Make sure that headers are not changed when
calling EmailMessage.message()'

def test_multiple_message_call(self):

    email = EmailMessage('Subject', 'Content', 'bounce@example.com', ['to@example.com'], headers={'From': 'from@example.com'})
    message = email.message()
    self.assertEqual(message['From'], 'from@example.com')
    message = email.message()
    self.assertEqual(message['From'], 'from@example.com')
