### Question:
TypeRenderUtils { public static String drawInterface(Class<?> clazz) { return StringUtils.concat(",", clazz.getInterfaces()); }  static String drawInterface(Class<?> clazz); static String drawParameters(Method method); static String drawParameters(Constructor constructor); static String drawParameters(String[] parameterTypes); static String drawReturn(Method method); static String drawExceptions(Method method); static String drawExceptions(Constructor constructor); static String drawExceptions(String[] exceptionTypes); static Element drawSuperClass(ClassDetailVO clazz); static Element drawClassLoader(ClassVO clazz); static Element drawTree(String[] nodes); static Element drawField(ClassDetailVO clazz, Integer expand); static String drawAnnotation(String... annotations); static String[] getAnnotations(Class<?> clazz); static String[] getAnnotations(Annotation[] annotations); static String[] getInterfaces(Class clazz); static String[] getSuperClass(Class clazz); static String[] getClassloader(Class clazz); static FieldVO[] getFields(Class clazz);  }### Answer:
@Test public void testDrawInterface() { assertThat(TypeRenderUtils.drawInterface(String.class), is(equalTo("java.io.Serializable,java.lang.Comparable,java.lang.CharSequence"))); assertThat(TypeRenderUtils.drawInterface(TestClass.class), is(equalTo("java.io.Serializable"))); assertThat(TypeRenderUtils.drawInterface(Serializable.class), is(equalTo(""))); }