Append additional headers, e.g., x-goog-user-project, shared across the classes inheriting AuthClient. This method should be used by any method that overrides getRequestMetadataAsync(), which is a shared helper for setting request information in both gRPC and HTTP API calls.
The main authentication interface. It takes an optional url which when present is the endpoint being accessed, and returns a Promise which resolves with authorization header fields.
The result has the form: { Authorization: 'Bearer <access_token_value>' }
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07 UTC."],[],[]]