Appears to silently strip texturecoordinates?

When running `save("test.ply", mesh)` where `mesh.texturecoordinates` is set to something nonempty, the resulting file does not contain any texture coordinates, there is no warning produced, and looking at https://github.com/JuliaIO/MeshIO.jl/blob/master/src/io/ply.jl, MeshIO doesn't seem to be aware of them.