class_docstr: Zeroes all anomaly scores whose absolute value is less than the threshold.
code: def to_simple_threshold(self):
      return self
  
imports: import bisect
  import logging
  import numpy
  from merlion.evaluate.anomaly import TSADMetric
  from merlion.post_process.base import PostRuleBase
  from merlion.utils import UnivariateTimeSeries, TimeSeries
label_desc: Use image node_id 4 for calling the Threshold obj's underlying member method code with example usage: obj.to_simple_threshold() and returns: self