One test was wrong. Diff:

-        TestVectors(   `[adzУ-Я]{4}`,    "DzюА",                    "y",   "$&", "DzЮа", "i"),
+        TestVectors(   `[adzУ-Я]{4}`,    "DzюЯ",                    "y",   "$&", "DzюЯ", "i"),