code: def _remapLangSys(langSys, featureRemap):
      if langSys.ReqFeatureIndex != 0xFFFF:
          langSys.ReqFeatureIndex = featureRemap[
              langSys.ReqFeatureIndex
          ]
      langSys.FeatureIndex = [
          featureRemap[index] for index in langSys.FeatureIndex
      ]
  
imports: from fontTools.misc.dictTools import hashdict
  from fontTools.misc.intTools import bit_count
  from fontTools.ttLib import newTable
  from fontTools.ttLib.tables import otTables
  from fontTools.ttLib.ttVisitor import TTVisitor
  from fontTools.otlLib.builder import buildLookup, buildSingleSubstSubtable
  from collections import OrderedDict
  from .errors import VarLibError, VarLibValidationError
label_desc: Use image node_id 20 for calling a global function with example usage: _remapLangSys(langSys, featureRemap) without return types