NewBaseAPIClient creates a new instance of the base API client implementation.

TokenProviderFromCreator creates a token provider out of token creator.

NoopTokenProvider is a token provider that returns an empty string which is ignored by `DoRequest`.

APIError describes an error during unsuccessful HTTP request to an API.

BaseAPIClient describes all basic HTTP client operations required to work with a JSON API.

TokenProvider is a function that gets the token string for each request.