WithDialContext() allows specifying custom dialer for hijacking and supposed to replace WithDialer(). WithDialer() is also updated to use WithDialContext(). client.Dialer() returns the dialer configured with WithDialContext(). Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp> Upstream-commit: edac92409a3b1d0cfb7f5c0e2d10b3bb71f27245 Component: engine