@GetMapping(produces = MediaType.TEXT_PLAIN_VALUE, path = "/test")
	public String echo(@RequestParam Optional<String> text) {
		return text.orElse("not-specified");
	}
Echo string.

@param text the text
@return the string
springdoc-openapi-tests/springdoc-openapi-javadoc-tests/src/test/java/test/org/springdoc/api/v30/app79/HelloController.java