code: private void validateDepDefinitionUniqueness(final List<FlowTriggerDependency> dependencies) {
      final Set<String> seen = new HashSet<>();
      for (final FlowTriggerDependency dep : dependencies) {
        final Map<String, String> props = dep.getProps();
        // set.add() returns false when there exists duplicate
        Preconditions.checkArgument(seen.add(dep.getType() + ":" + props.toString()), String.format
            ("duplicate dependency config %s found, dependency config should be unique",
                dep.getName()));
      }
    }
docs: check uniqueness of dependency type and params