I'm using go 1.6, x/net/webdav: golang/net@d75b190
goenv: GOARCH="amd64" GOBIN="" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/ibrahim" GORACE="" GOROOT="/usr/local/go" GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64" GO15VENDOREXPERIMENT="1" CC="clang" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fno-common" CXX="clang++" CGO_ENABLED="1"

webdav.File implementers can optionally implement webdav.DeadPropsHolder interface.I f you try to implement that interface, you have to use xml.Name as the key to map[xml.Name]webdav.Property, which is an internal package: golang.org/x/net/webdav/internal/xml. You can't reach that package outside of the webdav package.
/CC: @nigeltao