AllLevels returns all possible levels.

AllStages returns all possible stages.

ConvertStagesToStrings converts an array of stages to a string array.

ConvertStringSetToStages converts a string set to an array of stages.

EnforcePolicy drops any part of the event that doesn't conform to a policy level or omitStages and sets the event level accordingly.

InvertStages subtracts the given array of stages from all stages.

NewFakePolicyRuleEvaluator creates a fake policy rule evaluator that returns a constant level for all requests (for testing).

NewPolicyRuleEvaluator creates a new policy rule evaluator.

DefaultAuditLevel is the default level to audit at, if no policy rules are matched.