public void insertColumn(int beforeIndex, Column<T, ?> col, SafeHtml headerHtml,
                             SafeHtml footerHtml) {
        insertColumn(beforeIndex, col, new SafeHtmlHeader(headerHtml), new SafeHtmlHeader(footerHtml));
    }
Inserts a column into the table at the specified index with an associated
{@link SafeHtml} header and footer.

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