+ /**
+ * Convert a char (codepoint) to a string.
+ *
+ * @param ch the char
+ * @return the string
+ */
+ private String codePointString(final int ch) {
+ StringBuilder sb = new StringBuilder(1);
+ sb.append(Character.toChars(ch));
+ assert (Character.charCount(ch) == sb.length());
+ return sb.toString();
+ }
+