RadzenDataGrid - how to create a tooltip in column header using HeaderTooltip property?

Hi ,
There's HeaderTooltip property in DataGridColumn - but i cannot make it work to show and extend information about the column. (ie. i would like to put a definition of the column name with some formula etc.. in that tooltip).
i know i can use Tooltip Service with HeaderTemplate.. but as there is a property already i thought i don't have to create extra code but use that property. how to set itp?

i simply put HeaderTooltip="some text that explains the header". but it doesn't work

/// <summary>
        /// Gets or sets the header tooltip.
        /// </summary>
        /// <value>The header tooltip.</value>
        [Parameter]
        public string HeaderTooltip { get; set; }

You need to set ShowColumnTitleAsTooltip="false" for the DataGrid: