text: from ...registry import SCHEDULERS
  from .base import SchedulerBase
  
  
  @SCHEDULERS.register_module
  class ConstantScheduler(SchedulerBase):
      def __init__(self, scale=30.0):
          super(ConstantScheduler, self).__init__()
  
          self._end_s = scale
          assert self._end_s > 0.0
  
      def _get_scale(self, step, iters_per_epoch):
          return self._end_s
  