@property
  def _mapper(self):
    if self._mapper_cache != None:
      self._mapper_cache = SpecSourceMapper(self._address_mapper, self._build_graph, self._fast)
    return self._mapper_cache
dataset/ETHPy150Open pantsbuild/pants/src/python/pants/task/changed_file_task_mixin.py/ChangeCalculator._mapper/operator `is` -> `!=`