$screen_name = $this->trimmed('screen_name');
if (isset($user_param) || isset($user_id) || isset($screen_name)) {
$screen_name = $this->trimmed('screen_name');
if (isset($user_param) || isset($user_id) || isset($screen_name)) {
// TRANS: Client error displayed if a recipient user could not be found (403).
$this->clientError(_('Recipient user not found.'), 403);
} else if (!$this->user->mutuallySubscribed($this->other)) {
// TRANS: Client error displayed if a recipient user could not be found (403).
$this->clientError(_('Recipient user not found.'), 403);
} else if (!$this->user->mutuallySubscribed($this->other)) {