private List<String> tokenListToStringList(List<Token> tokens) {
		if (tokens.isEmpty()) {
			return Collections.<String> emptyList();
		}
		List<String> data = new ArrayList<String>();
		for (Token token : tokens) {
			data.add(token.data);
		}
		return data;
	}
Parse a stream definition.

@return the AST for the parsed stream
@throws StreamDefinitionException
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/stream/dsl/StreamConfigParser.java