Bug 221521 [Markers] New markers API needs to be pared down
We have too much API in some of the new classes and they can be moved to internals
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/MarkerCompletionField.java
private Image getImage(Object element) {
		switch (getDoneConstant((MarkerItem) element)) {
		case DONE:
			return getCompleteImage();
		case NOT_DONE:
			return MarkerSupportInternalUtilities
					.createImage(INCOMPLETE_IMAGE_PATH);
		default:
			return null;
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.provisional.views.markers.MarkerField#getValue(org.eclipse.ui.internal.provisional.views.markers.MarkerItem)
	 */
	public String getValue(MarkerItem item) {
		return MarkerSupportConstants.EMPTY_STRING;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.views.markers.MarkerField#update(org.eclipse.jface.viewers.ViewerCell)
	 */
	public void update(ViewerCell cell) {
		super.update(cell);
		cell.setImage(getImage(cell.getElement()));
	}
}