code: func RegisterDescriptorSetCompressed(serviceNames []string, compressedDescriptorSet []byte) {
  	registry.Lock()
  	defer registry.Unlock()
  	e := &entry{compressedBytes: compressedDescriptorSet}
  	for _, s := range serviceNames {
  		registry.entries[s] = e
  	}
  }
docs: // RegisterDescriptorSetCompressed registers a descriptor set for a set of services.
  // Called from code generated by go.chromium.org/luci/grpc/cmd/cproto
  //
  // compressedDescriptorSet must be a valid descriptor.FileDescriptorSet message
  // compressed wit gzip.
  // It must contain descriptions for all the services, their message types
  // and all transitive dependencies.
  //
  // This call is cheap.