Quiero elUILabel para comenzar desde arriba incluso si el texto es corto parece queNSTextAlignment no funciona

cell.textContent.text = comments[indexPath.row]
cell.textContent.textAlignment = 




func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    //post's section == 0

    if indexPath.section == 0 {
        let cell = tableView.dequeueReusableCellWithIdentifier("postCID", forIndexPath: indexPath) as! postCell
        cell.usernameLabel.text = "Steve Paul Jobs"
         cell.time.text = "9:42 PM"
         cell.commentsLabelCount.text = "12 Comments"
         cell.textContent.text = "Return the number of rows in the sectioReturn the number of rows in the sectioReturn the number of rows in the sectioReturn the number of rows in the sectioReturn the number of rows in the sectioReturn the number of rows in the sectio"

        cell.layoutSubviews()

    }

        let cell = tableView.dequeueReusableCellWithIdentifier("commentCID", forIndexPath: indexPath) as! commentCell
        // Configure the cell...
      cell.layoutSubviews()

    cell.usernameLabel.text = "Steve Paul Jobs"
    cell.time.text = "9:42 PM"
    cell.textContent.text = comments[indexPath.row]
     cell.textContent.textAlignment = NSTextAlignment.Left


        return cell



}


import UIKit

class commentCell: UITableViewCell {
    @IBOutlet weak var textContent: UILabel!
    @IBOutlet weak var time: UILabel!
    @IBOutlet weak var userImage: UIImageView!
    @IBOutlet weak var usernameLabel: UILabel!

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
    userImage.layer.cornerRadius = 2
    userImage.clipsToBounds = true

}
override func layoutSubviews() {
    super.layoutSubviews()
    textContent.sizeToFit()
}