@Override
    public final void setRowCount(int count) {
        setRowCount(count, true);
    }
Set the starting index of the current visible page. The actual page start
will be clamped in the range [0, getSize() - 1].

@param pageStart the index of the row that should appear at the start of
         the page
@see #setVisibleRange(Range)
@see #getPageStart()
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/AbstractHasData.java