googleapis.com – policysimulator

Policy Simulator is a collection of endpoints for creating, running, and viewing a Replay. A Replay is a type of simulation that lets you see how your members' access to resources might change if you changed your IAM policy. During a Replay, Policy Simulator re-evaluates, or replays, past access attempts under both the current policy and your proposed policy, and compares those results to determine how your members' access might change under the proposed policy.