Class clazz = compile("chars.c", "Chars");
Method method = clazz.getMethod("circle_name");
CharPtr ptr = (CharPtr) method.invoke(null);
assertThat(ptr.asString(), equalTo("Hello world"));
method = clazz.getMethod("test_first_char");
Integer result = (Integer) method.invoke(null);
assertThat(result, equalTo((int) 'h'));