Request router

The ray.serve.request_router module holds the base class, mixins, and data types for writing a custom request router.

serve.request_router.ReplicaID	A unique identifier for a replica.
serve.request_router.PendingRequest	A request that is pending execution by a replica.
serve.request_router.RunningReplica	Contains info on a running replica.
serve.request_router.FIFOMixin	Mixin for FIFO routing.
serve.request_router.LocalityMixin	Mixin for locality routing.
serve.request_router.MultiplexMixin	Mixin for multiplex routing.
serve.request_router.RequestRouter	Abstract interface for a request router (how the router calls it).