-// A provider proxy wraps a provider with rate-limiting logic. After
-// the wrapped provider receives a cloud.RateLimitError, the proxy
-// starts returning errors to callers immediately without calling
-// through to the wrapped provider.
-//
-//
-// TBD: Bootstrapping script via SSH, too? Future version.
-//
-// TBD: drain instance, keep instance alive
-// TBD: metrics, diagnostics
-// TBD: why dispatch token currently passed to worker?
-//
-// Metrics: queue size, time job has been in queued, #idle/busy/booting nodes
-// Timing in each step, and end-to-end
-// Metrics: boot/idle/alloc time and cost
+// An instance set proxy wraps a driver's instance set with
+// rate-limiting logic. After the wrapped instance set receives a
+// cloud.RateLimitError, the proxy starts returning errors to callers
+// immediately without calling through to the wrapped instance set.