public void assertFileContainsIgnoreCase(String data) {
		assertFileContainsIgnoreCase(data, STREAM_NAME);
	}
Asserts that the data stored by a file sink, whose name is based off the stream name,
is what was expected.  The assertion is case insensitive.

@param data The data expected in the file
spring-xd-integration-test/src/test/java/org/springframework/xd/integration/test/AbstractIntegrationTest.java