Method:

Method: Set the data for displaying. It will attempt to unserialize (There is a chance that some columns are serialized). This can be override in child classes for futher data transformation.

Method: Renders the checkbox for each row, this is the first column and it is named ID regardless of how the primary key is named (to keep the code simpler). The bulk actions will do the proper name transformation though using `$this->ID`.

Method: Returns the columns names for rendering. It adds a checkbox for selecting everything as the first column

Method: Get prepared LIMIT clause for items query

Method: Returns the number of items to offset/skip for this current view.

Method: Get prepared OFFSET clause for items query

Method: Prepares the ORDER BY sql statement. It uses `$this->sort_by` to know which columns are sortable. This requests validates the orderby $_GET parameter is a valid column and sortable. It will also use order (ASC|DESC) using DESC by default.

Method: Return the sortable column specified for this request to order the results by, if any.

Method: Return the sortable column order specified for this request.