class_docstr: Reader for OHCLV pricing data at a session frequency.
code: def data_frequency(self):
      return "session"
  
file_path: zipline/zipline/data/session_bars.py
imports: from abc import abstractproperty, abstractmethod
  from zipline.data.bar_reader import BarReader
label_desc: Use image node_id 1 for calling the SessionBarReader obj's underlying member method code with example usage: obj.data_frequency() and returns: str