code: def mergeFeatureLists(lst):
      d = {}
      for l in lst:
          for f in l:
              tag = f.FeatureTag
              if tag not in d:
                  d[tag] = []
              d[tag].append(f.Feature)
      ret = []
      for tag in sorted(d.keys()):
          rec = otTables.FeatureRecord()
          rec.FeatureTag = tag
          rec.Feature = mergeFeatures(d[tag])
          ret.append(rec)
      return ret
  
imports: from fontTools import ttLib
  from fontTools.ttLib.tables.DefaultTable import DefaultTable
  from fontTools.ttLib.tables import otTables
  from fontTools.merge.base import add_method, mergeObjects
  from fontTools.merge.util import *
  import logging
label_desc: Use image node_id 3 for calling a global function with example usage: mergeFeatureLists(lst) and returns: ret