@Test
	public void testCollidingModuleComposeWithOtherComposite() {
		module().compose("compositesource", "time | splitter");

		CommandResult result = getShell().executeCommand(
				"module compose compositesource --definition \"time | transform\"");
		assertEquals("There is already a module named 'compositesource' with type 'source'\n",
				result.getException().getMessage());

	}
This tests that options passed at usage time of a composed module are override definition values.
spring-xd-shell/src/test/java/org/springframework/xd/shell/command/AbstractModuleCommandsTests.java