class_docstr: Plotting object allows for visualization of absolute group bias metrics and
  relative disparities calculated by Aequitas Group(), Bias(), and Fairness()
  class instances.
docstr: Return nearest quartile for given value x.
code: def _nearest_quartile(x):
      """
      Return nearest quartile for given value x.
      """
      rounded = round(x * 4) / 4
      if rounded > x:
          return rounded
      else:
          return rounded + 1 / 4
  
imports: import logging
  import math
  import numpy
  import collections
  import seaborn
  import matplotlib.pyplot
  import matplotlib.colors
  import matplotlib.cm
  from aequitas import squarify_flipped
label_desc: Use image node_id 2 for calling the Plot obj's underlying member method code with example usage: obj._nearest_quartile(x) and returns: rounded, unknown