code: func (ctx *RequestCtx) IsTLS() bool {
  	// cast to (connTLSer) instead of (*tls.Conn), since it catches
  	// cases with overridden tls.Conn such as:
  	//
  	// type customConn struct {
  	//     *tls.Conn
  	//
  	//     // other custom fields here
  	// }
  	_, ok := ctx.c.(connTLSer)
  	return ok
  }
docs: // IsTLS returns true if the underlying connection is tls.Conn.
  //
  // tls.Conn is an encrypted connection (aka SSL, HTTPS).