code: def median_hilow(series, confidence_interval=0.95):
      """
      Median and a selected pair of outer quantiles having equal tail areas
  
      Parameters
      ----------
      series : pandas.Series
          Values
      confidence_interval : float
          Confidence interval in the range (0, 1).
      """
      tail = (1 - confidence_interval) / 2
      return pd.DataFrame(
          {
              "y": [np.median(series)],
              "ymin": np.percentile(series, 100 * tail),
              "ymax": np.percentile(series, 100 * (1 - tail)),
          }
      )
  
file_path: plotnine/plotnine/stats/stat_summary.py
imports: import numpy
  import pandas
  from .._utils import get_valid_kwargs, uniquecols
  from ..doctools import document
  from ..exceptions import PlotnineError
  from .stat import stat
label_desc: Use image node_id 5 for calling a global function with example usage: median_hilow(series, confidence_interval) and returns: pd