+// We need to make a private copy of the default http transport early
+// in initialization, then make copies of our private copy later. It
+// won't be safe to copy http.DefaultTransport itself later, because
+// its private mutexes might have already been used. (Without this,
+// the test suite sometimes panics "concurrent map writes" in
+// net/http.(*Transport).removeIdleConnLocked().)
+var defaultTransport = *(http.DefaultTransport.(*http.Transport))
+