Ability to use custom Sort in Custom Visualizations

I would like to have the API available for Custom Sort, the current API
http://stn.spotfire.com/stn/API.aspx?API=dxp%2fhtml%2fT_Spotfire_Dxp_Data_Transformations_SortRule.htm, sorts only ascending and descending


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For example in the professional client for the below data -

ID Value X Y
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A 15 5 5
B 20 5 5
C 14 5 5

If we make scatter plot for this data and sort by "ID"

Scatter plot order is "A" "B" "C"

but , if we change "custom sort order" like "B","C","A"

Then Scatter plot order is "B","C","A"
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I would like to have this API available for Custom Sort Order

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