fixes a row at the top of the datatable at runtime
|id||number|string||optional, the row id|
|state||boolean||optional, true - to move a row to the "frozen" block, false - to unfreeze a row|
Available only in PRO Edition
Note that if you don't pass any parameters to the method, all frozen rows will be unfrozen. The method is inapplicable if called for Datatable (or any successor) with Pager.