code: def efficacy(
      optimal_lost_magnitude, base_lost_magnitude, cur_lost_magnitude
  ):
      if base_lost_magnitude == optimal_lost_magnitude:
          eff = 1.0
      else:
          eff = (base_lost_magnitude - cur_lost_magnitude) / (
              base_lost_magnitude - optimal_lost_magnitude
          )
      return eff
  
imports: import numpy
  import time
  import subprocess
  import math
label_desc: Use image node_id 6 for calling a global function with example usage: efficacy(optimal_lost_magnitude, base_lost_magnitude, cur_lost_magnitude) and returns: eff