@RequestMapping(value = "/{kind}")
	public List<String> completions(@PathVariable("kind") CompletionKind kind,
			@RequestParam("start") String start,
			@RequestParam(value = "detailLevel", defaultValue = "1") int detailLevel) {
		return completionProvider.complete(kind, start, detailLevel);
	}
Return a list of possible completions given a prefix string that the user has started typing.

 @param kind the kind of definition that is being authored
 @param start the amount of text written so far
 @param detailLevel the level of detail the user wants in completions
                    (<i>e.g.</i> higher numbers may mean show 'hidden' options)
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/rest/CompletionsController.java