in src/main/java/com/twitter/nodes/Node.java [684:693]
private void setAllDependencies(Map<Enum, Node> depsMap) {
Preconditions.checkArgument(depsMap != null && !depsMap.isEmpty(),
"You can set with empty dependency map");
ImmutableMap<Enum, Node> allDependencies = addOptionalDeps(depsMap);
// check if all dependencies are provided
EnumSet unsetEnums = EnumSet.complementOf(EnumSet.copyOf(allDependencies.keySet()));
Preconditions.checkArgument(unsetEnums.isEmpty(),
"Required dependencies not set for node [" + getName() + "]: " + unsetEnums);
this.dependentNodesByName = allDependencies;
}