	private final HColor getBackColor(UmlDiagramType umlDiagramType, Style style) {
		if (EntityUtils.groupRoot(group))
			return null;

		final HColor result = group.getColors().getColor(ColorType.BACK);
		if (result != null)
			return result;

		final Stereotype stereo = group.getStereotype();

		if (UseStyle.useBetaStyle())
			return style.value(PName.BackGroundColor).asColor(skinParam.getThemeStyle(), skinParam.getIHtmlColorSet());

		final USymbol sym = group.getUSymbol() == null ? USymbols.PACKAGE : group.getUSymbol();
		final ColorParam backparam = umlDiagramType == UmlDiagramType.ACTIVITY ? ColorParam.partitionBackground
				: sym.getColorParamBack();
		final HColor c1 = skinParam.getHtmlColor(backparam, stereo, false);
		if (c1 != null)
			return c1;

		if (parentCluster == null)
			return null;

		return parentCluster.getBackColor(umlDiagramType, style);
	}
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.