code: def fields(self):
      return self.df.columns.tolist()
  
imports: from abc import ABCMeta, abstractmethod
  from collections import namedtuple
  import hashlib
  from textwrap import dedent
  import warnings
  from logbook import Logger
  import numpy
  import pandas
  from pandas import read_csv
  import pytz
  import requests
  from six import StringIO, iteritems, with_metaclass
  from zipline.errors import MultipleSymbolsFound, SymbolNotFound, ZiplineError
  from zipline.protocol import DATASOURCE_TYPE, Event
  from zipline.assets import Equity
label_desc: Use image node_id 2 for calling the PandasCSV obj's underlying member method code with example usage: obj.fields() and returns: self