Bug 330864 Add ability to find context for a UI element
bundles/org.eclipse.e4.core.contexts.debug/src/org/eclipse/e4/core/internal/contexts/debug/ui/ContextsView.java
public void refresh() {
		treeViewer.refresh();
	}
	@Focus
	public void setFocus() {
		treeViewer.getControl().setFocus();
	}
	protected ContextSnapshot snapshot;
	protected void makeSnapshot() {
		
		snapshot = new ContextSnapshot();
		diffButton.setEnabled(true);
	}
	protected void makeDiff() {
		if (snapshot == null)
			return;
		Map<EclipseContext, Set<Computation>> snapshotDiff = snapshot.diff();
		if (snapshotDiff == null) {
			MessageBox dialog = new MessageBox(snapshotButton.getShell(), SWT.OK);
			dialog.setMessage(ContextMessages.noDiffMsg);
			dialog.setText(ContextMessages.diffDialogTitle);
			dialog.open();
			return;
		}
		LeaksDialog dialog = new LeaksDialog(snapshotButton.getShell());
		dialog.setInput(snapshotDiff);
		dialog.open();
	}
}