/// <summary>
 /// Write the string value to the destiation.
 /// Used for direct content
 /// </summary>
 /// <param name="value"></param>
 private void writeText(string value)
 {
     if (RtfParser.IsNewGroup())
     {
         _rtfDoc.Add(new RtfDirectContent("{"));
         RtfParser.SetNewGroup(false);
     }
     if (value.Length > 0)
     {
         _rtfDoc.Add(new RtfDirectContent(value));
     }
 }