lib/Segment.php
public static function alias(array $message) {
    self::checkClient();
    $userId = !empty($message["userId"]);
    $previousId = !empty($message["previousId"]);
    self::assert($userId && $previousId, "Segment::alias() requires both userId and previousId");

    return self::$client->alias($message);
  }
public static function alias(array $message) {
    self::checkClient();
    $userId = !empty($message["userId"]);
    $previousId = !empty($message["previousId"]);
    self::assert($userId && $previousId, "Segment::alias() requires both userId and previousId");

    return self::$client->alias($message);
  }
public static function alias ( array $ message ) { self :: checkClient ( ) ; $ userId = ! empty ( $ message [ "userId" ] ) ; $ previousId = ! empty ( $ message [ "previousId" ] ) ; self :: assert ( $ userId && $ previousId , "Segment::alias() requires both userId and previousId" ) ; return self :: $ client -> alias ( $ message ) ; }
Aliases the user id from a temporary id to a permanent one

@param  array $from      user id to alias from
@return boolean whether the alias call succeeded
Aliases the user id from a temporary id to a permanent one