Bug 327765 EPartService will hide a part of another perspective
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
}
			return element.isVisible();
		}
		return false;
	}
	private boolean isInContainer(MUIElement element) {
		return isInContainer(getContainer(), element);
	}
	private boolean isInContainer(MElementContainer<?> container, MUIElement element) {
		for (Object object : container.getChildren()) {
			if (object == element) {
				return true;
			} else if (object instanceof MElementContainer<?>) {
				if (isInContainer((MElementContainer<?>) object, element)) {
					return true;
				}
			} else if (object instanceof MPlaceholder) {
				MUIElement ref = ((MPlaceholder) object).getRef();
				if (ref == element) {
					return true;
				} else if (ref instanceof MElementContainer<?>) {
					if (isInContainer((MElementContainer<?>) ref, element)) {
						return true;
					}
				}
			} else if (object instanceof MPerspective) {
				MPerspective persp = (MPerspective) object;
				for (MWindow dw : persp.getWindows()) {
					if (isInContainer(dw, element))
						return true;