private boolean peekToken(TokenKind desiredTokenKind, boolean consumeIfMatched) {
		if (!moreTokens()) {
			return false;
		}
		Token t = peekToken();
		if (t.kind == desiredTokenKind) {
			if (consumeIfMatched) {
				tokenStreamPointer++;
			}
			return true;
		}
		else {
			return false;
		}
	}
Return the concatenation of the data of many tokens.
spring-xd-dirt/src/main/java/org/springframework/xd/dirt/stream/dsl/StreamConfigParser.java