code: public DependencyContainer add(Dependency dependency)
    {
      if (dependency == this)
        throw new IllegalArgumentException("Can't add self as a dependency.");
      
      if (! _dependencyList.contains(dependency))
        _dependencyList.add(dependency);
  
      // server/1d0w
      // XXX: _lastCheckTime = 0;
  
      return this;
    }
docs: Adds a dependency.