@Override
			public String resolveStringValue(String strVal) {
				helper.replacePlaceholders(strVal, placeholderResolver);
				return strVal;
			}
Used as a replacement for "}", so that we can show that the default is a placeholder, but still avoid infinite
recursion.
spring-xd-module/src/main/java/org/springframework/xd/module/options/DefaultModuleOptionsMetadataCollector.java