NewClient creates a new Client for S3.

WithS3 configures a Client with a custom S3 implementation.

AuthConfig matches Langley format.

Client implements a backend.Client for S3.

Config defines s3 connection specific parameters and authetication credentials.

S3 defines the operations we use in the s3 api.

Option allows setting optional Client parameters.

UserAuthConfig defines authentication configuration overlayed by Langley.