in src/main/java/com/twitter/nodes/Node.java [351:357]
public final Set<? extends Enum> getOptionalDependencies() {
if (dependentNodesByName.isEmpty()) {
return Collections.emptySet();
}
Enum firstEnum = dependentNodesByName.keySet().iterator().next();
return getOptionalDependenciesForClass(firstEnum.getClass());
}