def METHOD_NAME(self):
    """Defaults for optional fields are correct"""
    invitation = ProjectInvitation.objects.create(
        email="janedoe@example.com",
        project=self.project,
        role="editor",
    )
    self.assertIsNone(invitation.invited_by)
    self.assertIsNone(invitation.accepted_by)
    self.assertIsNone(invitation.accepted_at)
    self.assertIsNone(invitation.revoked_at)
    self.assertIsNone(invitation.resent_at)
    self.assertEqual(invitation.status, ProjectInvitation.Status.PENDING)