code: def interpolate_cff2_PrivateDict(topDict, interpolateFromDeltas):
      pd_blend_lists = (
          "BlueValues",
          "OtherBlues",
          "FamilyBlues",
          "FamilyOtherBlues",
          "StemSnapH",
          "StemSnapV",
      )
      pd_blend_values = (
          "BlueScale",
          "BlueShift",
          "BlueFuzz",
          "StdHW",
          "StdVW",
      )
      for fontDict in topDict.FDArray:
          pd = fontDict.Private
          vsindex = pd.vsindex if (hasattr(pd, "vsindex")) else 0
          for key, value in pd.rawDict.items():
              if (key in pd_blend_values) and isinstance(value, list):
                  delta = interpolateFromDeltas(vsindex, value[1:])
                  pd.rawDict[key] = otRound(value[0] + delta)
              elif (key in pd_blend_lists) and isinstance(
                  value[0], list
              ):
                  """If any argument in a BlueValues list is a blend list,
                  then they all are. The first value of each list is an
                  absolute value. The delta tuples are calculated from
                  relative master values, hence we need to append all the
                  deltas to date to each successive absolute value."""
                  delta = 0
                  for i, val_list in enumerate(value):
                      delta += otRound(
                          interpolateFromDeltas(vsindex, val_list[1:])
                      )
                      value[i] = val_list[0] + delta
  
file_path: catboost/contrib/python/fonttools/fontTools/varLib/mutator.py
imports: from fontTools.misc.fixedTools import floatToFixedToFloat, floatToFixed
  from fontTools.misc.roundTools import otRound
  from fontTools.pens.boundsPen import BoundsPen
  from fontTools.ttLib import TTFont, newTable
  from fontTools.ttLib.tables import ttProgram
  from fontTools.ttLib.tables._g_l_y_f import GlyphCoordinates, flagOverlapSimple, OVERLAP_COMPOUND
  from fontTools.varLib.models import supportScalar, normalizeLocation, piecewiseLinearMap
  from fontTools.varLib.merger import MutatorMerger
  from fontTools.varLib.varStore import VarStoreInstancer
  from fontTools.varLib.mvar import MVAR_ENTRIES
  from fontTools.varLib.iup import iup_delta
  import fontTools.subset.cff
  import os.path
  import logging
  from io import BytesIO
label_desc: Use image node_id 1 for calling a global function with example usage: interpolate_cff2_PrivateDict(topDict, interpolateFromDeltas) without return types