private void coalesceCellProperties() {
        dependsOnSelection = false;
        handlesSelection = false;
        isInteractive = false;
        for (HasCell<T, ?> column : tableBuilder.getColumns()) {
            Cell<?> cell = column.getCell();
            if (cell.dependsOnSelection()) {
                dependsOnSelection = true;
            }
            if (cell.handlesSelection()) {
                handlesSelection = true;
            }
            if (isColumnInteractive(column)) {
                isInteractive = true;
            }
        }
    }
Coalesce the various cell properties (dependsOnSelection, handlesSelection,
isInteractive) into a table policy.
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/AbstractCellTable.java