[Dir] Cache

[Dir] Credentials

[Dir] HttpHandler

[Dir] Middleware

[Dir] Subscriber

[File] AccessToken.php

[File] ApplicationDefaultCredentials.php

[File] CacheTrait.php

[File] CredentialsLoader.php

[File] FetchAuthTokenCache.php

[File] FetchAuthTokenInterface.php

[File] GCECache.php

[File] GetQuotaProjectInterface.php

[File] Iam.php

[File] OAuth2.php

[File] ProjectIdProviderInterface.php

[File] ServiceAccountSignerTrait.php

[File] SignBlobInterface.php

[File] UpdateMetadataInterface.php