public function test_invalid_characters_are_stripped_from_tokens()
{
$email = new BP_Email('activity-at-message');
$default_tokens = $email->get_tokens();
$email->set_tokens(array('te{st}1' => 'hello world'));
$this->assertSame(array_keys(array('test1' => 'hello world') + $default_tokens), array_keys($email->get_tokens()));
}