'Specifying dates or message-ids in the extra headers overrides the
default values (#9233)'

def test_message_header_overrides(self):

    headers = {'date': 'Fri,    09    Nov    2001    01:08:47    -0000', 'Message-ID': 'foo'}
    email = EmailMessage('subject', 'content', 'from@example.com', ['to@example.com'], headers=headers)
    self.assertMessageHasHeaders(email.message(), {('Content-Transfer-Encoding', '7bit'), ('Content-Type', 'text/plain;    charset="utf-8"'), ('From', 'from@example.com'), ('MIME-Version', '1.0'), ('Message-ID', 'foo'), ('Subject', 'subject'), ('To', 'to@example.com'), ('date', 'Fri,    09    Nov    2001    01:08:47    -0000')})
