@Override
        public boolean equals(final Object other) {
            if (!(other instanceof ViewData)) {
                return false;
            }
            final ViewData vd = (ViewData) other;
            return equalsOrNull(lastValue, vd.lastValue) && equalsOrNull(curValue, vd.curValue);
        }
Return true if the last and current values of this ViewData object
are equal to those of the other object.
stroom-core-client-widget/src/main/java/stroom/cell/valuespinner/client/ValueSpinnerCell.java