Where is Border component in Flex/mx library?

I have an old Flex app build with the Halo library. Now that Halo was changed to mx library, it makes the old Border component stop working and I'm unable to build the project anymore.

Even when I try to开发者_C百科 change the library to MX, the Border cannot build.

Does anyone know how to fix this?

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You're using the Programmatic Skin Border class? The class is in the same location in my Flex 4 source that it is in in my Flex 3 source. They may have changed it's namespace location, but it seems unlikely. Perhaps if you share some code with us?