@Test
	public void expressions_xd159() {
		StreamNode ast = parse("foo | transform --expression=--payload | bar");
		ModuleNode mn = ast.getModule("transform");
		Properties props = mn.getArgumentsAsProperties();
		assertEquals("--payload", props.get("expression"));
	}
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