public function addRelated($username, $label = '')
{
$username = \Twitter\Helpers\Validators\ScreenName::trim($username);
if ($username) {
// normalize passed parameter
$comparison_username = strtolower($username);
if (!isset($this->related[$comparison_username])) {
if ($this->validate_inputs) {
if (\Twitter\Helpers\Validators\ScreenName::isValid($username)) {
$this->related[$comparison_username] = trim($label);
}
} else {
$this->related[$comparison_username] = trim($label);
}
}
}
return $this;
}