set type(type) {
        this.schema.type = type;
        this.behavior.reindex();
    }
@summary Get or set the type of the column's header.
@desc Setting the type updates the filter which typically uses this information for proper collation.

@todo: Instead of using `this._type`, put on data source like the other essential properties. In this case, sorter could use the info to choose a comparator more intelligently and efficiently.
@type {string}