server.go
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
}
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
}
// IsTLS returns true if the underlying connection is tls.Conn.
//
// tls.Conn is an encrypted connection (aka SSL, HTTPS).