@Override
            public String format(String str)
            {
                return toCamelCase(str).append('_').toString();
            }
camel-case with trailing underscore.
<p>

<pre>
some_foo/SomeFoo/someFoo becomes someFoo_
</pre>
protostuff-compiler/src/main/java/io/protostuff/compiler/Formatter.java