added nn/schedulear NewLRScheduler

CHANGELOG.md

@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- Added nn/scheduler NewLRScheduler()
 
 
 ## [Nofix]

nn/scheduler.go

@@ -44,6 +44,10 @@ type LRScheduler struct {
 	scheduler scheduler
 }
 
+func NewLRScheduler(s scheduler) *LRScheduler {
+	return &LRScheduler{s}
+}
+
 // Step updates optimizer learning rate.
 func (s *LRScheduler) Step(opts ...SchedulerOption) {
 	s.scheduler.SetLRs(opts...)