release method
      
void
release()
      
     
    
    
Implementation
void release() {
  if (_released) {
    return;
  }
  {
    if (sourceImage != null) {
      sourceImage!.release();
    }
  }
  {
    if (extractedDocument != null) {
      extractedDocument!.release();
    }
  }
  _released = true;
}