@Test
	public void duplicateImplicitLabels() {
		checkForParseError("http | filter | transform | transform | file",
				XDDSLMessages.DUPLICATE_LABEL, 28, "transform", "transform", 2, "transform", 3);
	}
Parse streams and verify either the correct abstract syntax tree is produced or the current exception comes out.

@author Andy Clement
@author David Turanski
spring-xd-dirt/src/test/java/org/springframework/xd/dirt/stream/dsl/StreamConfigParserTests.java