code: def getValidPart(self, df):
      level = 0
      signal = list(self.mModels[level].keys())[0]
      lEngine = self.mModels[level][signal]
      lFrameFit = lEngine.mSignalDecomposition.mBestModel.mTimeInfo.mSplit.getValidPart(
          df
      )
      return lFrameFit
  
imports: import pandas
  import numpy
  from ..None import ForecastEngine
  from .None import Options
  from .None import Perf
  from .None import Utils
  from .None import Plots
  import time
label_desc: Use image node_id 17 for calling the cSignalHierarchy obj's underlying member method code with example usage: obj.getValidPart(df) and returns: lFrameFit