code: def interpolateFromDeltasAndScalars(deltas, scalars):
      delta = 0.0
      for d, s in zip(deltas, scalars):
          if not s:
              continue
          delta += d * s
      return delta
  
imports: from fontTools.misc.roundTools import noRound, otRound
  from fontTools.misc.intTools import bit_count
  from fontTools.ttLib.tables import otTables
  from fontTools.varLib.models import supportScalar
  from fontTools.varLib.builder import buildVarRegionList, buildVarStore, buildVarRegion, buildVarData
  from functools import partial
  from collections import defaultdict
  from heapq import heappush, heappop
label_desc: Use image node_id 5 for calling the VarStoreInstancer obj's underlying member method code with example usage: obj.interpolateFromDeltasAndScalars(deltas, scalars) and returns: delta