Howto: Set top space to match vertical align attached image with text

gistfile1.swift

class TDTextAttachment: NSTextAttachment {
   
   var topSpace: Float = 0.0
    
   convenience init(image: UIImage, topSpace: Float = 0.0) {
      self.init()
      self.image = image
      self.topSpace = 0.0
   }
    
   override func attachmentBoundsForTextContainer(textContainer: NSTextContainer, proposedLineFragment lineFrag: CGRect, glyphPosition position: CGPoint, characterIndex charIndex: Int) -> CGRect {
      let imageSize = image!.size
        
      return CGRect(x: 0.0, y: CGFloat(topSpace), width: imageSize.width, height: imageSize.height)
   }
}