@Override
    public boolean isConsumed(final CellPreviewEvent<?> event) {
        final NativeEvent nativeEvent = event.getNativeEvent();
        if (MOUSEDOWN.equals(nativeEvent.getType()) && MouseUtil.isPrimary(nativeEvent)) {
            final Element element = nativeEvent.getEventTarget().cast();
            return ElementUtil.hasClassName(element, COPY_CLASS_NAME, 5) ||
                   ElementUtil.hasClassName(element, OPEN_CLASS_NAME, 5);
        }
        return false;
    }
@param showIcon         Set to true to show the type icon next to the text
@param cellTextFunction Function to provide the cell 'text' in HTML form.
@param docRefFunction   Function to provide a doc ref if the value can give us one.
@param cssClassFunction Function to provide additional css class names.
stroom-core-client/src/main/java/stroom/data/client/presenter/DocRefCell.java