Bug 327925 Deprecate EPartService's deactivate(MPart) method
It has been marked as @noreference for some time. Now that part activation history has been implemented and the hidePart(*) methods have been altered to take care of this, the deactivate(MPart) method should be removed.
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
}
			} else if (object instanceof MPlaceholder) {
				MPlaceholder placeholder = (MPlaceholder) object;
				MUIElement ref = placeholder.getRef();
				if (ref == part) {
					return placeholder;
				}
			}
		}
		if (container instanceof MWindow) {
			MWindow win = (MWindow) container;
			for (MWindow dw : win.getWindows()) {
				MPlaceholder placeholder = getLocalPlaceholder(dw, part);
				if (placeholder != null) {
					return placeholder;
				}
			}
		}
		if (container instanceof MPerspective) {
			MPerspective persp = (MPerspective) container;
			for (MWindow dw : persp.getWindows()) {
				MPlaceholder placeholder = getLocalPlaceholder(dw, part);
				if (placeholder != null) {
					return placeholder;
				}
			}
		}
		return null;
	}
	public void switchPerspective(MPerspective perspective) {