code: def test_aggregate_capital_gains(self):
      # Setup
      tkr = "FXAIX"
      dat = yf.Ticker(tkr, session=self.session)
      start = "2017-12-31"
      end = "2019-12-31"
      interval = "3mo"
  
      dat.history(start=start, end=end, interval=interval)
  
imports: from .context import yfinance
  from .context import session_gbl
  import unittest
  import os
  import datetime
  import pytz
  import numpy
  import pandas
label_desc: Use image node_id 23 for calling the TestPriceHistory obj's underlying member method code with example usage: obj.test_aggregate_capital_gains() without return types