docstr: the split point for lower outliers should be at provided percentile
code: def test_outlier_lower_percentile(self):
      """the split point for lower outliers should be at provided percentile"""
  
      arr = np.array(range(100001))
      np.random.shuffle(arr)
      d = Discretiser(method="outlier", outlier_percentile=0.2)
      d.fit(arr)
      assert d.numeric_split_points[0] == 20000
  
imports: import math
  import numpy
  import pytest
  from causalnex.discretiser import Discretiser
label_desc: Use image node_id 3 for calling the TestOutlier obj's underlying member method code with example usage: obj.test_outlier_lower_percentile() without return types