diff --git a/token_writer.go b/token_writer.go
index ed580ef..f6dffa4 100644
--- a/token_writer.go
+++ b/token_writer.go
@@ -23,6 +23,7 @@
 	TextEnd     func(int)
 	Flush       func() error
 	Token       func(int, []rune)
+	// Fail        func(int)
 }
 
 // Create a new token writer based on the options
@@ -36,6 +37,8 @@
 
 	tw := &TokenWriter{}
 
+	// tw.Fail = func(_ int) {}
+
 	// Collect token positions and maybe tokens
 	if flags&(TOKEN_POS|SENTENCE_POS) != 0 {