code: def __call__(self, df, other):
      if isinstance(df, DATAFRAME_TYPE):
          self.output_types = [OutputType.dataframe]
          return self._call_dataframe(df, other)
      else:
          self.output_types = [OutputType.series]
          return self._call_series(df, other)
  
file_path: mars/mars/dataframe/merge/append.py
imports: import pandas
  from ...None import opcodes
  from ...core import OutputType, recursive_tile
  from ...serialization.serializables import BoolField
  from ..datasource.dataframe import from_pandas
  from ..indexing.iloc import DataFrameIlocGetItem, SeriesIlocGetItem
  from ..utils import parse_index, standardize_range_index
  from ..operands import DataFrameOperand, DataFrameOperandMixin, DATAFRAME_TYPE, SERIES_TYPE
label_desc: Use image node_id 8 for calling the DataFrameAppend obj's underlying member method code with example usage: obj.__call__(df, other) and returns: self, self