old_contents: from AlphaTwirl import AlphaTwirl
  import HeppyResult
  from HeppyResultReader import HeppyResultReader
  from Events import Events
  import Binning
  import Counter
  from Combine import Combine
  from CombineIntoList import CombineIntoList, countsToList
  from CombineIntoPandasDataFrame import CombineIntoPandasDataFrame, countsToDataFrame
  from WriteListToFile import WriteListToFile
  from WritePandasDataFrameToFile import WritePandasDataFrameToFile
  import EventReader
  import ProgressBar
  from EventBuilder import EventBuilder
  from buildBinningFromTbl import buildBinningFromTbl
  
new_contents: from AlphaTwirl import AlphaTwirl
  import HeppyResult
  from HeppyResultReader import HeppyResultReader
  from Events import Events
  import Binning
  import Counter
  from Combine import Combine
  from CombineIntoList import CombineIntoList, countsToList
  from WriteListToFile import WriteListToFile
  import EventReader
  import ProgressBar
  from EventBuilder import EventBuilder
  
  try:
      from CombineIntoPandasDataFrame import CombineIntoPandasDataFrame, countsToDataFrame
      from WritePandasDataFrameToFile import WritePandasDataFrameToFile
      from buildBinningFromTbl import buildBinningFromTbl
  except ImportError:
      pass
  
subject: add a try clause in case pandas is not available