func NewDefaultCredentials() credentials.Bundle {
	c := &creds{
		newPerRPCCreds: func() credentials.PerRPCCredentials {
			ctx, cancel := context.WithTimeout(context.Background(), tokenRequestTimeout)
			defer cancel()
			perRPCCreds, err := oauth.NewApplicationDefault(ctx)
			if err != nil {
				logger.Warningf("google default creds: failed to create application oauth: %v", err)
			}
			return perRPCCreds
		},
	}
	bundle, err := c.NewWithMode(internal.CredsBundleModeFallback)
	if err != nil {
		logger.Warningf("google default creds: failed to create new creds: %v", err)
	}
	return bundle
}
NewDefaultCredentials returns a credentials bundle that is configured to work
with google services.

This API is experimental.
package google
import (
	"context"
	"fmt"
	"time"
	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/credentials/alts"
	"google.golang.org/grpc/credentials/oauth"
	"google.golang.org/grpc/grpclog"
	"google.golang.org/grpc/internal"
)
const tokenRequestTimeout = 30 * time.Second
var logger = grpclog.Component("credentials")