agent/dockerclient/dockerauth/ecr.go
func (key *cacheKey) String() string {
	return fmt.Sprintf("%s-%s-%s-%s", key.roleARN, key.region, key.registryID, key.endpointOverride)
}
func (key *cacheKey) String() string {
	return fmt.Sprintf("%s-%s-%s-%s", key.roleARN, key.region, key.registryID, key.endpointOverride)
}
// String formats the cachKey as a string