Bug 201906 [Viewers] 3.4 ColumnViewerEditor leaks ViewerCell instances.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColumnViewerEditor.java
focusListener = new FocusAdapter() {
							public void focusLost(FocusEvent e) {
								applyEditorValue();
							}
						};
					}
					control.addFocusListener(focusListener);
				}
				mouseListener = new MouseAdapter() {
					public void mouseDown(MouseEvent e) {
						
						
						if (e.time <= activationTime) {
							control.removeMouseListener(mouseListener);
							cancelEditing();
							handleDoubleClickEvent();
						} else if (mouseListener != null) {
							control.removeMouseListener(mouseListener);
						}
					}
				};
				if (activationTime != 0
						&& (feature & KEEP_EDITOR_ON_DOUBLE_CLICK) == 0) {
					control.addMouseListener(mouseListener);
				}
				if (tabeditingListener == null) {
					tabeditingListener = new TraverseListener() {
						public void keyTraversed(TraverseEvent e) {
							if ((feature & DEFAULT) != DEFAULT) {
								processTraverseEvent(cell.getColumnIndex(),