protected String messageToString(Message message) {
        switch (message.getMessageType()) {
            case SYSTEM:
                return message.getContent();
            case USER:
                return humanPrompt + message.getContent();
            case ASSISTANT:
                return assistantPrompt + message.getContent();
            case TOOL:
                throw new IllegalArgumentException(TOOL_EXECUTION_NOT_SUPPORTED_FOR_WAI_MODELS);
        }

        throw new IllegalArgumentException("Unknown message type: " + message.getMessageType());
    }
@Test
	public void testSingleAssistantMessage() {
		Message assistantMessage = new AssistantMessage("Assistant message");
		String expected = "Assistant message";
		Assert.assertEquals(expected, converter.messageToString(assistantMessage));
	}