public void addColumn(Column<T, ?> col, SafeHtml headerHtml) {
        insertColumn(getColumnCount(), col, headerHtml);
    }
Adds a column to the end of the table with an associated {@link SafeHtml}
header.

@param col        the column to be added
@param headerHtml the associated header text, as safe HTML
stroom-core-client-widget/src/main/java/com/google/gwt/user/cellview/client/AbstractCellTable.java