private Set<String> set(String str) {
        Set<String> symbols = new HashSet<>();
        for (String symbol : str.split(",")) {
            symbols.add(symbol);
        }
        return symbols;
    }
Basic tests of DependencyBuilder
@author Tony Vaagenes
config-model/src/test/java/com/yahoo/vespa/model/builder/xml/dom/chains/DependenciesBuilderTest.java