If this method uses the Wylie representation, you get an infinite recursion

when you do a TMW->Wylie conversion for a document with glyphs that
have no known Wylie.

source/org/thdl/tib/text/DuffCode.java

@@ -162,13 +162,13 @@ public final class DuffCode {
 	}
 /**
  * @param TMW if this DuffCode represents a TMW glyph, not a TM glyph
- * @return a string representation of this object */
+ * @return a string representation of this object that does not refer
+ * to its Wylie representation (because the TMW->Wylie error messages
+ * call upon this when there is none, and you don't want an infinite
+ * loop (manifesting as a StackOverflowError)) */
 	public String toString(boolean TMW) {
         boolean[] err = new boolean[] { false };
-        String wylie = TibetanMachineWeb.getWylieForGlyph(this, err);
-        if (err[0]) wylie = "undefined";
-		return "<duffcode wylie="
-            + wylie + " font="
+		return "<duffcode font="
             + (TMW
                ? TibetanMachineWeb.tmwFontNames
                : TibetanMachineWeb.tmFontNames)[fontNum]