code: def time_groupby_mean(self, engine):
      self.gb_ewm.mean(engine=engine)
  
imports: import warnings
  import numpy
  import pandas
  from .pandas_vb_common import setup
label_desc: Use image node_id 2 for calling the GroupbyEWMEngine obj's underlying member method code with example usage: obj.time_groupby_mean(engine) without return types