code: def __call__(self, df):
      return df.expanding(**self.params)
  
imports: from collections import OrderedDict
  from ....serialization.serializables import BoolField, Int32Field, Int64Field, StringField
  from ....utils import pd_release_version
  from ...utils import validate_axis
  from ..core import Window
label_desc: Use image node_id 6 for calling the Expanding obj's underlying member method code with example usage: obj.__call__(df) and returns: df