@Override
    public void execute(Template.Fragment fragment, Writer writer) throws IOException {
        StringWriter sr = new StringWriter();
        kebab.execute(fragment, sr);

        StringBuffer sb = sr.getBuffer();
        for( int i = 0 ; i < sb.length() ; i++ ) {
            char c = sb.charAt(i);

            if ( c == '-') {
                sb.setCharAt(i, '_');
            }
            else if ( !Character.isUpperCase(c)) {
                sb.setCharAt(i, Character.toUpperCase(c));
            }
        }

        writer.write(sb.toString());
    }
@Test
    void whenExecute_thenSuccess() throws IOException {

        JavaConstantLambda sub = new JavaConstantLambda();

        StringWriter writer = new StringWriter();
        Template.Fragment frag = mock(Template.Fragment.class);
        when(frag.execute())
          .thenReturn("ANormalString");
        sub.execute(frag, writer);

        String result = writer.toString();
        assertEquals("A_NORMAL_STRING", result);

    }