code: def test_max_median_exposure(self, positions, expected):
      alloc_summary = get_max_median_position_concentration(positions)
      assert_frame_equal(expected, alloc_summary)
  
file_path: pyfolio/pyfolio/tests/test_pos.py
imports: from unittest import TestCase
  from nose_parameterized import parameterized
  from collections import OrderedDict
  import os
  import gzip
  from pandas import Series, DataFrame, date_range, Timestamp, read_csv
  from pandas.util.testing import assert_frame_equal
  from numpy import arange, zeros_like, nan
  import warnings
  from pyfolio.utils import to_utc, to_series, check_intraday, detect_intraday, estimate_intraday
  from pyfolio.pos import get_percent_alloc, extract_pos, get_sector_exposures, get_max_median_position_concentration
label_desc: Use image node_id 4 for calling the PositionsTestCase obj's underlying member method code with example usage: obj.test_max_median_exposure(positions, expected) without return types