Bug 326300 EPartService's activate(MPart) method may not work if you activate the window's active part
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
}
			} else if (child instanceof MElementContainer<?>) {
				MElementContainer<MUIElement> match = findContainer((MElementContainer<?>) child,
						element);
				if (match != null) {
					return match;
				}
			}
		}
		return null;
	}
	private MUIElement getRemoveTarget(MUIElement element) {
		MPlaceholder sharedRef = element.getCurSharedRef();
		if (sharedRef == null) {
			return findRemoveTarget(getContainer(), element);
		}
		return sharedRef;
	}
	private MUIElement findRemoveTarget(MElementContainer<?> container, MUIElement element) {
		for (Object child : container.getChildren()) {
			if (child instanceof MPlaceholder) {
				MPlaceholder placeholder = (MPlaceholder) child;
				if (placeholder.getRef() == element) {
					return placeholder;
				}
			}
		}
		return element;
	}
	private MPart showPart(PartState partState, MPart providedPart, MPart localPart) {