docs: @Nonnull
    @ReturnsMutableCopy
    public static ICommonsOrderedSet <IProxySettings> findAllProxySettings (@Nullable final String sProtocol,
                                                                            @Nullable final String sHostName,
                                                                            @CheckForSigned final int nPort)
    {
      final ICommonsOrderedSet <IProxySettings> ret = new CommonsLinkedHashSet <> ();
      for (final IProxySettingsProvider aProvider : getAllProviders ())
        ret.addAll (aProvider.getAllProxySettings (sProtocol, sHostName, nPort));
      return ret;
    }