Is there any way to get interpolation type in Photoshop animation using JSX script?

Unfortunately I found only how to set the value (for example for the current keyframe or for all keyframes like in the function below).

Any attempts to read the value give an error both in CS6 and in CC2018.

I hope this is also useful.

//set_animation_interpolation(false)
function set_animation_interpolation(lin)
    {
    try {
        // select all keyframes
        var r = new ActionReference();
        r.putEnumerated( stringIDToTypeID( "animationKey" ), charIDToTypeID( "Ordn" ), charIDToTypeID( "Al  " ) );
        var d = new ActionDescriptor();
        d.putReference( charIDToTypeID( "null" ), r );
        executeAction( charIDToTypeID( "slct" ), d, DialogModes.NO );
        var r = new ActionReference();
        r.putProperty( charIDToTypeID( "Prpr" ), stringIDToTypeID( "animInterpStyle" ) );
        r.putEnumerated( stringIDToTypeID( "animationKey" ), charIDToTypeID( "Ordn" ), charIDToTypeID( "Trgt" ) );
        var d = new ActionDescriptor();
        d.putReference( charIDToTypeID( "null" ), r );
        d.putEnumerated( charIDToTypeID( "T   " ), stringIDToTypeID( "animInterpStyle" ), lin?stringIDToTypeID("linear"):stringIDToTypeID("hold") );
        executeAction( charIDToTypeID( "setd" ), d, DialogModes.NO );
        // deselect all keyframes
        var r = new ActionReference();
        r.putEnumerated( stringIDToTypeID( "animationKey" ), charIDToTypeID( "Ordn" ), charIDToTypeID( "None" ) );
        var d = new ActionDescriptor();
        d.putReference( charIDToTypeID( "null" ), r );
        executeAction( charIDToTypeID( "slct" ), d, DialogModes.NO );
        }
    catch(e) { alert(e) }
    }