### Question:
MessageFrame extends DefaultByteBufHolder implements Frame { @Override public String toString() { return StringUtil.simpleClassName(this) + "[messages=" + messages + ']'; } MessageFrame(final String message);  MessageFrame(final String... messages);  MessageFrame(final List<String> messages); List<String> messages(); @Override MessageFrame copy(); @Override MessageFrame duplicate(); @Override MessageFrame retain(); @Override MessageFrame retain(int increment); @Override String toString();  }### Answer:
@Test public void content() { final MessageFrame messageFrame = new MessageFrame("first", "second"); assertThat(messageFrame.content().toString(CharsetUtil.UTF_8), equalTo("a[\"first\",\"second\"]")); messageFrame.release(); }