InitializeApiCollectors registers and zeroes a Prometheus histogram, populating all path, code, and method labels from the provided maps in its parameters.

InitializeGrpcCollectorsFromPackage registers and zeroes a Prometheus histogram, populating all service and method labels by ranging through the package containing the provided FileDescriptor.

InitializeGrpcCollectorsFromServer registers and zeroes a Prometheus histogram, finding all service and method labels from the provided gRPC server.

NewConnectionTrackingListener registers a new Prometheus gauge with an unique connection type label and wraps an existing listener to track when connections are accepted and closed.

NewGrpcRequestRecorder creates a requestRecorder struct which is used to measure gRPC client request latencies.

NewStatsHandler takes a request latency metric (prometheus.ObserverVec) and returns a grpc stats.Handler that updates the provided metric with the request latency.

SplitMethodName returns the service and the method name when given the full method name as provided by the grpc request handler.

StatusFromError retrieves the *status.Status from the provided error.

testableObserverVec allows us to assert which observations are being made with which labels.