code: def _execute_cum_alpha_coeff(
      cls, op: "DataFrameEwmAgg", in_data, order, final=True
  ):
      exec_cache = cls._exec_cache[op.key]
      cache_key = ("cum_alpha_coeff", order, id(in_data))
      summary = None
  
      try:
          result = exec_cache[cache_key]
      except KeyError:
          alphas = cls._calc_data_alphas(op, in_data, order)
          result = alphas.cumsum()
          exec_cache[cache_key] = result
  
      if final:
          if op.output_agg:
              summary = result.ffill()[-1:]
      return result, summary
  
imports: from collections import namedtuple
  import numpy
  import pandas
  from ....None import opcodes
  from ....serialization.serializables import BoolField, Float64Field
  from ..aggregation import BaseDataFrameExpandingAgg
label_desc: Use image node_id 8 for calling the DataFrameEwmAgg obj's underlying member method code with example usage: obj._execute_cum_alpha_coeff(cls, op, in_data, order, final) and returns: result,  summary