type Config struct {
	// Audience is the Secure Token Service (STS) audience which contains the resource name for the workforce pool and
	// the provider identifier in that pool.
	Audience string
	// RefreshToken is the optional OAuth 2.0 refresh token. If specified, credentials can be refreshed.
	RefreshToken string
	// TokenURL is the optional STS token exchange endpoint for refresh. Must be specified for refresh, can be left as
	// None if the token can not be refreshed.
	TokenURL string
	// TokenInfoURL is the optional STS endpoint URL for token introspection.
	TokenInfoURL string
	// ClientID is only required in conjunction with ClientSecret, as described above.
	ClientID string
	// ClientSecret is currently only required if token_info endpoint also needs to be called with the generated GCP
	// access token. When provided, STS will be called with additional basic authentication using client_id as username
	// and client_secret as password.
	ClientSecret string
	// Token is the OAuth2.0 access token. Can be nil if refresh information is provided.
	Token string
	// Expiry is the optional expiration datetime of the OAuth 2.0 access token.
	Expiry time.Time
	// RevokeURL is the optional STS endpoint URL for revoking tokens.
	RevokeURL string
	// QuotaProjectID is the optional project ID used for quota and billing. This project may be different from the
	// project used to create the credentials.
	QuotaProjectID string
	Scopes         []string
}