code: def _featureVariationRecordIsUnique(rec, seen):
      conditionSet = []
      conditionSets = (
          rec.ConditionSet.ConditionTable
          if rec.ConditionSet is not None
          else []
      )
      for cond in conditionSets:
          if cond.Format != 1:
              # can't tell whether this is duplicate, assume is unique
              return True
          conditionSet.append(
              (
                  cond.AxisIndex,
                  cond.FilterRangeMinValue,
                  cond.FilterRangeMaxValue,
              )
          )
      # besides the set of conditions, we also include the FeatureTableSubstitution
      # version to identify unique FeatureVariationRecords, even though only one
      # version is currently defined. It's theoretically possible that multiple
      # records with same conditions but different substitution table version be
      # present in the same font for backward compatibility.
      recordKey = frozenset(
          [rec.FeatureTableSubstitution.Version] + conditionSet
      )
      if recordKey in seen:
          return False
      else:
          seen.add(recordKey)  # side effect
          return True
  
file_path: catboost/contrib/python/fonttools/fontTools/varLib/instancer/featureVars.py
imports: from fontTools.ttLib.tables import otTables
  from copy import deepcopy
  import logging
label_desc: Use image node_id 1 for calling a global function with example usage: _featureVariationRecordIsUnique(rec, seen) and returns: False, True, True