uri.go
func (u *URI) UpdateBytes(newURI []byte) {
	u.requestURI = u.updateBytes(newURI, u.requestURI)
}
func (u *URI) UpdateBytes(newURI []byte) {
	u.requestURI = u.updateBytes(newURI, u.requestURI)
}
// UpdateBytes updates uri.
//
// The following newURI types are accepted:
//
//     * Absolute, i.e. http://foobar.com/aaa/bb?cc . In this case the original
//       uri is replaced by newURI.
//     * Absolute without scheme, i.e. //foobar.com/aaa/bb?cc. In this case
//       the original scheme is preserved.
//     * Missing host, i.e. /aaa/bb?cc . In this case only RequestURI part
//       of the original uri is replaced.
//     * Relative path, i.e.  xx?yy=abc . In this case the original RequestURI
//       is updated according to the new relative path.