feat: Add Warmup function for starting background refresh (#163)

Author: kurtisvg

dialer.go

@@ -251,6 +251,13 @@ func (d *Dialer) EngineVersion(ctx context.Context, instance string) (string, er
 	return e, nil
 }
 
+// Warmup starts the background refresh neccesary to connect to the instance. Use Warmup
+// to start the refresh process early if you don't know when you'll need to call "Dial".
+func (d *Dialer) Warmup(ctx context.Context, instance string, opts ...DialOption) error {
+	_, err := d.instance(instance)
+	return err
+}
+
 // newInstrumentedConn initializes an instrumentedConn that on closing will
 // decrement the number of open connects and record the result.
 func newInstrumentedConn(conn net.Conn, closeFunc func()) *instrumentedConn {