Approach for bundeling string helpers into templates in Seam Render

BundledHelpersTest.java

public class BundledHelpersTest {

    @Test
    public void testStringUtils() throws Exception {
        testBundledHelper("TheInpu...",             "@{render.abbreviate('TheInputString', 10)}");
        testBundledHelper("...putSt...",            "@{render.abbreviate('TheInputString', 5, 11)}");
        testBundledHelper("TheInputString",         "@{render.capitalize('TheInputString')}");
        testBundledHelper("   TheInputString   ",   "@{render.center('TheInputString', 20)}");
        testBundledHelper("TheInputString",         "@{render.defaultString('TheInputString', 'BlahBlah')}");
        testBundledHelper("BlahBlah",               "@{render.defaultString('', 'BlahBlah')}");
        testBundledHelper("BlahBlah",               "@{render.defaultString(null, 'BlahBlah')}");
        testBundledHelper("The Input String",       "@{render.join(new String[]{'The', 'Input', 'String'}, ' ')}");
        testBundledHelper("      TheInputString",   "@{render.leftPad('TheInputString', 20)}");
        testBundledHelper("XXXXXXTheInputString",   "@{render.leftPad('TheInputString', 20, 'X')}");
        testBundledHelper("theinputstring",         "@{render.lowerCase('TheInputString')}");
        testBundledHelper("TheOutputString",        "@{render.replace('TheInputString', 'In', 'Out')}");
        testBundledHelper("TheInputString      ",   "@{render.rightPad('TheInputString', 20)}");
        testBundledHelper("TheInputStringXXXXXX",   "@{render.rightPad('TheInputString', 20, 'X')}");
        testBundledHelper(new String[]{"TheI", "putStri", "g"}, "@{render.split('TheInputString', 'n')}");
        testBundledHelper(new String[]{"The", "Input", "String"}, "@{render.split('The Input String')}");
        testBundledHelper("tHEiNPUTsTRING",         "@{render.swapCase('TheInputString')}");
        testBundledHelper("TheInputString",         "@{render.trim('  TheInputString    ')}");
        testBundledHelper("theInputString",         "@{render.uncapitalize('TheInputString')}");
        testBundledHelper("THEINPUTSTRING",         "@{render.upperCase('TheInputString')}");
    }

    private void testBundledHelper(Object expectedResult, String mvelExpression) throws SecurityException, NoSuchMethodException {
        ParserContext ctx = prepareParserContext();
        CompiledTemplate template = CustomTemplateCompiler.compileTemplate(mvelExpression, ctx);
        Object result = TemplateRuntime.execute(template);
        if (result instanceof Object[]) {
            assertArrayEquals((Object[]) expectedResult, (Object[]) result);
        } else {
            assertEquals(expectedResult, result);
        }
    }

    private ParserContext prepareParserContext() throws NoSuchMethodException, SecurityException {
        ParserContext ctx = new ParserContext();
        ctx.addImport("render", StringUtils.class);
        return ctx;
    }
}