code: def timestamp(self):
      return datetime.datetime.combine(
          self.collection_ts.date(), datetime.datetime.min.time()
      )
  
imports: import datetime
  from abc import ABCMeta, abstractmethod
  import lore
  from lore.env import require
  from lore.util import convert_df_columns_to_json
  import pandas
  import inflection
label_desc: Use image node_id 3 for calling the BaseFeatureExporter obj's underlying member method code with example usage: obj.timestamp() and returns: datetime