passthroughMapper for arrow shapes

[begüm a.]

I have different arrow shapes in my network and i already have the "sourceArrowShape" and "targetArrowShape" defined in my XGMML file.

I tried using the passthrough mapper like this:

            var visual_style = {
                    edges: {
                        sourceArrowShape: { passthroughMapper: { attrName: "EDGE_SOURCE_ARROW_SHAPE" } },
                        targetArrowShape: { passthroughMapper: { attrName: "EDGE_TARGET_ARROW_SHAPE" } }

                           }
            };

,but it does not seem to work. i used the attr name as it is indicated in the XGMML file. What am i missing?