code: def test_get_max_drawdown_begins_first_day(self, px):
      rets = px.pct_change()
      drawdowns = timeseries.gen_drawdown_table(rets, top=1)
      self.assertEqual(drawdowns.loc[0, "Net drawdown in %"], 25)
  
imports: from __future__ import division
  import os
  from unittest import TestCase
  from nose_parameterized import parameterized
  from numpy.testing import assert_allclose, assert_almost_equal
  from pandas.util.testing import assert_series_equal
  import numpy
  import pandas
  from ..None import timeseries
  from pyfolio.utils import to_utc, to_series
  import gzip
label_desc: Use image node_id 1 for calling the TestDrawdown obj's underlying member method code with example usage: obj.test_get_max_drawdown_begins_first_day(px) without return types