@Test
	public void expressions_xd159_4() {
		StreamNode ast = parse("foo |  transform --expression=\"'Hello, world!'\" | bar");
		ModuleNode mn = ast.getModule("transform");
		Properties props = mn.getArgumentsAsProperties();
		assertEquals("'Hello, world!'", props.get("expression"));
		ast = parse("foo |  transform --expression='''Hello, world!''' | bar");
		mn = ast.getModule("transform");
		props = mn.getArgumentsAsProperties();
		assertEquals("'Hello, world!'", props.get("expression"));
		// Prior to the change for XD-1613, this error should point to the comma:
		// checkForParseError("foo |  transform --expression=''Hello, world!'' | bar", XDDSLMessages.UNEXPECTED_DATA,
		// 37);
		// but now it points to the !
		checkForParseError("foo |  transform --expression=''Hello, world!'' | bar", XDDSLMessages.UNEXPECTED_DATA, 44);
	}
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