@Test
	public void testInterpolation() throws Exception {
		moduleOptions.add(new ModuleOption("foo", "d"));
		moduleOptions.add(new ModuleOption("bar", "d").withDefaultValue("here"));
		moduleOptions.add(new ModuleOption("fizz", "d").withDefaultValue("there"));

		Map<String, String> userValues = new HashMap<String, String>();
		userValues.put("foo", "one");
		userValues.put("bar", "two");

		PropertySource<?> ps = moduleOptions.interpolate(userValues).asPropertySource();
		assertThat((String) ps.getProperty("foo"), equalTo("one"));
		assertThat((String) ps.getProperty("bar"), equalTo("two"));
		assertThat(ps.getProperty("bang"), nullValue());
		assertThat((String) ps.getProperty("fizz"), equalTo("there"));

	}
Test for {@link SimpleModuleOptionsMetadata} behavior.

@author Eric Bottard
spring-xd-module/src/test/java/org/springframework/xd/module/options/SimpleModuleOptionsMetadataTests.java