unsafe int INativeScintilla.GetTextRange(ref TextRange tr)
 {
     fixed(TextRange* trp = &tr)
         return (int)_ns.SendMessageDirect(Constants.SCI_GETTEXTRANGE, IntPtr.Zero, (IntPtr)trp);
 }
 unsafe void INativeScintilla.GetStyledText(ref TextRange tr)
 {
     fixed(TextRange* trp = &tr)
         _ns.SendMessageDirect(Constants.SCI_GETSTYLEDTEXT, IntPtr.Zero, (IntPtr)trp);
 }