src/vs/workbench/contrib/scm/browser/scmViewPane.ts/SCMTreeFilter/filter
class SCMTreeFilter:	filter(element: TreeElement): boolean {
		if (ResourceTree.isResourceNode(element)) {
			return true;
		} else if (isSCMResourceGroup(element)) {
			return element.elements.length > 0 || !element.hideWhenEmpty;
		} else {
			return true;
		}
	}